refactor(custody): drop the single-implementation CustodyStore trait

Reviewed-on: #102
Reviewed-by: Stas <business@jexter.tech>

AGENTS.md

@@ -1,13 +1,16 @@
 # AGENTS.md
 
-This file provides guidance to Codex (Codex.ai/code) when working with code in this repository.
+Guidance for coding agents (Claude Code, Codex, …) working in this repository.
 
 ## Project Overview
 
-Arbiter is a **permissioned signing service** for cryptocurrency wallets. It consists of:
+Arbiter is a **permissioned signing service** for cryptocurrency wallets:
+
 - **`server/`** — Rust gRPC daemon that holds encrypted keys and enforces policies
-- **`operator/`** — Flutter desktop app (macOS/Windows) with a Rust backend via Rinf
+- **`useragent/`** — Flutter app (desktop + mobile + web targets) with a Rust core via `flutter_rust_bridge`
-- **`protobufs/`** — Protocol Buffer definitions shared between server and client
+- **`protobufs/`** — Protocol Buffer definitions shared between server and clients
+- **`docs/`** — `ARCHITECTURE.md` (peer types, flows, threat model) and `IMPLEMENTATION.md`; treat them as the design source of truth and update them when behaviour changes
+- **`scripts/`** — helper scripts, e.g. `gen_erc20_registry.py`
 
 The vault never exposes key material; it only produces signatures when requests satisfy configured policies.
 
@@ -18,7 +21,7 @@ Tools are managed via [mise](https://mise.jdx.dev/). Install all required tools:
 mise install
 ```
 
-Key versions: Rust 1.93.0 (with clippy), Flutter 3.38.9-stable, protoc 29.6, diesel_cli 2.3.6 (sqlite).
+Key versions live in `mise.toml` (currently Rust 1.95.0 with clippy, Flutter 3.41.7-stable, protoc 29.6, diesel_cli 2.3.7 with `sqlite-bundled`, Python 3.14). Also provided there: `cargo-nextest`, `cargo-audit`, `cargo-vet`, `cargo-shear`, `cargo-mutants`, `cargo-features-manager`, `cargo-edit`, `ast-grep`, `flutter_rust_bridge_codegen`.
 
 ## Server (Rust workspace at `server/`)
 
@@ -26,10 +29,14 @@ Key versions: Rust 1.93.0 (with clippy), Flutter 3.38.9-stable, protoc 29.6, die
 
 | Crate | Purpose |
 |---|---|
-| `arbiter-proto` | Generated gRPC stubs + protobuf types; compiled from `protobufs/*.proto` via `tonic-prost-build` |
+| `arbiter-proto` | Generated gRPC stubs + protobuf types (`tonic-prost-build`); also `ArbiterUrl`, `home_path()`, `BOOTSTRAP_PATH` |
-| `arbiter-server` | Main daemon — actors, DB, EVM policy engine, gRPC service implementation |
+| `arbiter-crypto` | Shared crypto primitives: `authn` (ML-DSA), `safecell` (hardened memory), `hashing::Hashable`, re-exported `x-wing` |
-| `arbiter-operator` | Rust client library for the operator side of the gRPC protocol |
+| `arbiter-macros` | `#[derive(Hashable)]` — canonical hashing of structs for the DB integrity layer |
-| `arbiter-client` | Rust client library for SDK clients |
+| `arbiter-server` | Main daemon — actors, peers, DB, EVM policy engine, gRPC service implementation |
+| `arbiter-client` | Rust client library for SDK clients (`ArbiterClient`, EVM wallet, key storage) |
+| `arbiter-tokens-registry` | Generated ERC-20 token registry used by token-transfer policies |
+
+Workspace lints (`server/Cargo.toml`) are strict: most of clippy `pedantic`/`nursery` plus a large restriction set. `as` casts, indexing/slicing, `dbg!`, float arithmetic and undocumented `unsafe` are denied or warned — expect to add an `#[expect(..., reason = "...")]` rather than to silence a lint globally.
 
 ### Common Commands
 
@@ -42,54 +49,78 @@ cargo build
 # Run the server daemon
 cargo run -p arbiter-server
 
-# Run all tests (preferred over cargo test)
+# Run all tests (preferred over cargo test; CI uses --all-features)
 cargo nextest run
 
 # Run a single test
 cargo nextest run <test_name>
 
-# Lint
+# Lint (CI runs it with -D warnings)
-cargo clippy
+cargo clippy --all -- -D warnings
 
 # Security audit
 cargo audit
 
+# Supply-chain review (config in server/supply-chain/)
+cargo vet
+
 # Check unused dependencies
 cargo shear
 
-# Run snapshot tests and update snapshots
+# Mutation testing
-cargo insta review
+cargo mutants
 ```
 
+### CI
+
+Woodpecker pipelines in `.woodpecker/` run on `server/**` changes: `server-lint` (clippy), `server-test` (nextest, `--all-features`), `server-audit`, `server-vet`, plus `useragent-analyze` for the Flutter app.
+
 ### Architecture
 
-The server is actor-based using the **kameo** crate. All long-lived state lives in `GlobalActors`:
+The server is actor-based using the **kameo** crate. Long-lived state lives in `GlobalActors` (`src/actors/mod.rs`):
 
-- **`Bootstrapper`** — Manages the one-time bootstrap token written to `~/.arbiter/bootstrap_token` on first run.
+- **`Bootstrapper`** — one-time bootstrap token, written to `~/.arbiter/bootstrap_token` on first run
-- **`Vault`** — Holds the encrypted root key and manages the Sealed/Unsealed vault state machine. On unseal, decrypts the root key into a `memsafe` hardened memory cell.
+- **`Vault`** — encrypted root key and the Sealed/Unsealed state machine; on unseal decrypts the root key into a `memsafe`-backed `SafeCell`
-- **`FlowCoordinator`** — Coordinates cross-connection flow between operators and SDK clients.
+- **`FlowCoordinator`** — cross-connection flow between operators and SDK clients
-- **`EvmActor`** — Handles EVM transaction policy enforcement and signing.
+- **`OperatorRegistry`** — tracks currently connected operators
+- **`EvmActor`** — EVM transaction policy enforcement and signing
+- **`events`** — a `kameo_actors::MessageBus` (`DeliveryStrategy::Guaranteed`) for cross-actor notifications
 
-Per-connection actors live under `actors/operator/` and `actors/client/`, each with `auth` (challenge-response authentication) and `session` (post-auth operations) sub-modules.
+Per-connection state lives under **`src/peers/`**, not `actors/`: `peers/client/` and `peers/operator/`, each with `auth` (challenge-response) and `session` (post-auth) sub-modules; the operator side additionally has `vault_gate/` for the unseal handshake.
 
-**Database:** SQLite via `diesel-async` + `bb8` connection pool. Schema managed by embedded Diesel migrations in `crates/arbiter-server/migrations/`. DB file lives at `~/.arbiter/arbiter.sqlite`. Tests use a temp-file DB via `db::create_test_pool()`.
+The gRPC surface lives in **`src/grpc/`**, split per peer (`client/`, `operator/`, `common/`) and per direction (`inbound.rs` — requests to the daemon, `outbound.rs` — server-initiated streams), with `request_tracker.rs` correlating the two.
+
+EVM logic is in `src/evm/`: `policies/ether_transfer/`, `policies/token_transfers/`, `abi.rs`, `safe_signer.rs`.
+
+**Database:** SQLite via `diesel-async` + `bb8`. Schema in `src/db/schema.rs`, models in `src/db/models.rs`, embedded migrations in `crates/arbiter-server/migrations/`. DB file lives at `~/.arbiter/arbiter.sqlite`; tests use a temp-file DB via `db::create_test_pool()`.
+
+Entity ids are newtypes generated by the `declare_id!` macro in `db::models` (`OperatorId`, `ChainId`, …), each a `#[repr(transparent)]` wrapper over `i32` with `to_raw`/`from_raw`. Pass these around instead of bare `i32`.
+
+**Row integrity:** sensitive rows are covered by an HMAC-SHA256 envelope (`src/crypto/integrity/`, table `integrity_envelope`), keyed from the vault root key. A struct becomes coverable by deriving `arbiter_macros::Hashable` and implementing `Integrable` (`KIND` + `VERSION`). When adding or changing a covered entity, keep the derive and the payload version in sync — a mismatch surfaces as `PayloadVersionMismatch` or `MacMismatch` at runtime.
 
 **Cryptography:**
-- Authentication: ed25519 (challenge-response, nonce-tracked per peer)
+- Authentication: **ML-DSA-87** (post-quantum, `arbiter-crypto::authn::v1`), challenge-response with per-peer nonce tracking
-- Encryption at rest: XChaCha20-Poly1305 (versioned via `scheme` field for transparent migration on unseal)
+- Encryption at rest: XChaCha20-Poly1305, versioned modules (`crypto/encryption/v1.rs`) with a `schema_version` column for transparent migration on unseal
 - Password KDF: Argon2
-- Unseal transport: X25519 ephemeral key exchange
+- Unseal transport: X25519 ephemeral key exchange (`peers/operator/vault_gate/`); `x-wing` (hybrid PQ KEM) is available via `arbiter-crypto`
-- TLS: self-signed certificate (aws-lc-rs backend), fingerprint distributed via `ArbiterUrl`
+- TLS: self-signed certificate (rustls + aws-lc-rs, `prefer-post-quantum`), fingerprint distributed via `ArbiterUrl`
 
-**Protocol:** gRPC with Protocol Buffers. The `ArbiterUrl` type encodes host, port, CA cert, and bootstrap token into a single shareable string (printed to console on first run).
+Crypto modules are versioned by convention: `mod.rs` re-exports the current `vN`. Add a `v(N+1)` rather than editing an existing version in place.
+
+**Protocol:** gRPC with Protocol Buffers. `ArbiterUrl` encodes host, port, CA cert and bootstrap token into a single shareable string (printed to console on first run).
 
 ### Proto Regeneration
 
-When `.proto` files in `protobufs/` change, rebuild to regenerate:
+`arbiter-proto/build.rs` compiles `arbiter.proto`, `operator.proto`, `client.proto` and `evm.proto` (with their `shared/`, `operator/`, `client/` includes) on build:
 ```sh
 cd server && cargo build -p arbiter-proto
 ```
 
+Dart protobuf stubs are generated separately, from the repo root:
+```sh
+mise run codegen   # protoc --dart_out=grpc:useragent/lib/proto
+```
+
 ### Database Migrations
 
 ```sh
@@ -100,6 +131,8 @@ diesel migration generate <name> --migration-dir crates/arbiter-server/migration
 diesel migration run --migration-dir crates/arbiter-server/migrations
 ```
 
+Pre-release policy: there is a single `init` migration and no deployed databases yet, so schema changes are made by editing that migration directly instead of stacking new ones. Regenerate `src/db/schema.rs` after changing it.
+
 ### Code Conventions
 
 **`#[must_use]` Attribute:**
@@ -121,29 +154,23 @@ pub fn verify(&self, nonce: i32, context: &[u8], signature: &Signature) -> bool
 
 This forces callers to either use the return value or explicitly ignore it with `let _ = ...;`, preventing silent failures.
 
-## Operator (Flutter + Rinf at `operator/`)
+## User Agent (Flutter + flutter_rust_bridge at `useragent/`)
 
-The Flutter app uses [Rinf](https://rinf.cunarist.org) to call Rust code. The Rust logic lives in `operator/native/hub/` as a separate crate that uses `arbiter-operator` for the gRPC client.
+The Flutter app calls Rust through [flutter_rust_bridge](https://cjycode.com/flutter_rust_bridge/) 2.12.0. The Rust side is the `rust_lib_arbiter` crate at `useragent/rust/`; everything exposed to Dart is declared in `useragent/rust/src/api/` and lands in `useragent/lib/src/rust/` (see `useragent/flutter_rust_bridge.yaml`). Dart UI code is organised as `lib/features/`, `lib/screens/`, `lib/widgets/`, `lib/providers/`, `lib/theme/`, with routing in `lib/router.dart` (`router.gr.dart` is generated).
-
-Communication between Dart and Rust uses typed **signals** defined in `operator/native/hub/src/signals/`. After modifying signal structs, regenerate Dart bindings:
-
-```sh
-cd operator && rinf gen
-```
 
 ### Common Commands
 
 ```sh
-cd operator
+cd useragent
 
-# Run the app (macOS or Windows)
+# Run the app
 flutter run
 
-# Regenerate Rust↔Dart signal bindings
+# Regenerate Rust↔Dart bindings after editing rust/src/api/
-rinf gen
+mise run codegen        # flutter_rust_bridge_codegen generate
 
-# Analyze Dart code
+# Analyze Dart code (also run in CI)
 flutter analyze
 ```
 
-The Rinf Rust entry point is `operator/native/hub/src/lib.rs`. It spawns actors defined in `operator/native/hub/src/actors/` which handle Dart↔server communication via signals.
+Note: `app/` contains only stale generated Flutter artifacts and is not the application source.

mise.lock

@@ -152,5 +152,8 @@ url = "https://github.com/astral-sh/python-build-standalone/releases/download/20
 provenance = "github-attestations"
 
 [[tools.rust]]
-version = "1.95.0"
+version = "1.98.1"
 backend = "core:rust"
+
+[tools.rust.options]
+components = "clippy,rust-analyzer"

mise.toml

@@ -4,7 +4,7 @@
 "cargo:cargo-vet" = "0.10.2"
 flutter = "3.41.7-stable"
 protoc = "29.6"
-rust = { version = "1.95.0", components = "clippy,rust-analyzer" }
+rust = { version = "latest", components = "clippy,rust-analyzer" }
 "cargo:cargo-features-manager" = "0.12.0"
 "cargo:cargo-nextest" = "0.9.133"
 "cargo:cargo-shear" = "latest"

server/Cargo.lock

@@ -24,7 +24,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d122413f284cf2d62fb1b7db97e02edb8cda96d769b16e443a4f6195e35662b0"
 dependencies = [
  "crypto-common 0.1.7",
- "generic-array",
+ "generic-array 0.14.7",
 ]
 
 [[package]]
@@ -504,7 +504,7 @@ dependencies = [
  "async-trait",
  "auto_impl",
  "either",
- "elliptic-curve",
+ "elliptic-curve 0.13.8",
  "k256",
  "thiserror",
 ]
@@ -771,6 +771,7 @@ dependencies = [
  "proptest",
  "prost-types",
  "rand 0.10.1",
+ "rand_core 0.10.1",
  "rcgen",
  "restructed",
  "rstest",
@@ -786,6 +787,7 @@ dependencies = [
  "tonic",
  "tracing",
  "tracing-subscriber",
+ "vsss-rs",
  "x25519-dalek 2.0.1",
 ]
 
@@ -820,7 +822,7 @@ dependencies = [
  "ark-serialize 0.3.0",
  "ark-std 0.3.0",
  "derivative",
- "num-bigint",
+ "num-bigint 0.4.6",
  "num-traits",
  "paste",
  "rustc_version 0.3.3",
@@ -840,7 +842,7 @@ dependencies = [
  "derivative",
  "digest 0.10.7",
  "itertools 0.10.5",
- "num-bigint",
+ "num-bigint 0.4.6",
  "num-traits",
  "paste",
  "rustc_version 0.4.1",
@@ -861,7 +863,7 @@ dependencies = [
  "digest 0.10.7",
  "educe",
  "itertools 0.13.0",
- "num-bigint",
+ "num-bigint 0.4.6",
  "num-traits",
  "paste",
  "zeroize",
@@ -903,7 +905,7 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "db2fd794a08ccb318058009eefdf15bcaaaaf6f8161eb3345f907222bac38b20"
 dependencies = [
- "num-bigint",
+ "num-bigint 0.4.6",
  "num-traits",
  "quote",
  "syn 1.0.109",
@@ -915,7 +917,7 @@ version = "0.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7abe79b0e4288889c4574159ab790824d0033b9fdcb2a112a3182fac2e514565"
 dependencies = [
- "num-bigint",
+ "num-bigint 0.4.6",
  "num-traits",
  "proc-macro2",
  "quote",
@@ -928,7 +930,7 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09be120733ee33f7693ceaa202ca41accd5653b779563608f1234f78ae07c4b3"
 dependencies = [
- "num-bigint",
+ "num-bigint 0.4.6",
  "num-traits",
  "proc-macro2",
  "quote",
@@ -953,7 +955,7 @@ checksum = "adb7b85a02b83d2f22f89bd5cac66c9c89474240cb6207cb1efc16d098e822a5"
 dependencies = [
  "ark-std 0.4.0",
  "digest 0.10.7",
- "num-bigint",
+ "num-bigint 0.4.6",
 ]
 
 [[package]]
@@ -965,7 +967,7 @@ dependencies = [
  "ark-std 0.5.0",
  "arrayvec",
  "digest 0.10.7",
- "num-bigint",
+ "num-bigint 0.4.6",
 ]
 
 [[package]]
@@ -1195,6 +1197,12 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4c7f02d4ea65f2c1853089ffd8d2787bdbc63de2f0d29dedbcf8ccdfa0ccd4cf"
 
+[[package]]
+name = "base16ct"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd307490d624467aa6f74b0eabb77633d1f758a7b25f12bceb0b22e08d9726f6"
+
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -1283,7 +1291,7 @@ version = "0.10.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3078c7629b62d3f0439517fa394996acacc5cbc91c5a20d8c658e77abd503a71"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.7",
 ]
 
 [[package]]
@@ -1552,6 +1560,12 @@ version = "0.8.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
 
+[[package]]
+name = "cpubits"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "15b85f9c39137c3a891689859392b1bd49812121d0d61c9caf00d46ed5ce06ae"
+
 [[package]]
 name = "cpufeatures"
 version = "0.2.17"
@@ -1612,19 +1626,35 @@ version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0dc92fb57ca44df6db8059111ab3af99a63d5d0f8375d9972e319a379c6bab76"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.7",
  "rand_core 0.6.4",
  "subtle",
  "zeroize",
 ]
 
+[[package]]
+name = "crypto-bigint"
+version = "0.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a52aa3fcda4e6302a9f48734f234d35d4721b96f8fe07d073f07ce9df4f0271"
+dependencies = [
+ "cpubits",
+ "ctutils",
+ "hybrid-array",
+ "num-traits",
+ "rand_core 0.10.1",
+ "serdect 0.4.3",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "crypto-common"
 version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.7",
  "rand_core 0.6.4",
  "typenum",
 ]
@@ -1646,6 +1676,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7d5515a3834141de9eafb9717ad39eea8247b5674e6066c404e8c4b365d2a29e"
 dependencies = [
  "cmov",
+ "subtle",
 ]
 
 [[package]]
@@ -1808,7 +1839,7 @@ dependencies = [
  "asn1-rs",
  "displaydoc",
  "nom",
- "num-bigint",
+ "num-bigint 0.4.6",
  "num-traits",
  "rusticata-macros",
 ]
@@ -1927,7 +1958,7 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3dd60d1080a57a05ab032377049e0591415d2b31afd7028356dbf3cc6dcb066"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.7",
 ]
 
 [[package]]
@@ -2005,9 +2036,9 @@ checksum = "ee27f32b5c5292967d2d4a9d7f1e0b0aed2c15daded5a60300e4abb9d8020bca"
 dependencies = [
  "der 0.7.10",
  "digest 0.10.7",
- "elliptic-curve",
+ "elliptic-curve 0.13.8",
  "rfc6979",
- "serdect",
+ "serdect 0.2.0",
  "signature 2.2.0",
  "spki 0.7.3",
 ]
@@ -2039,20 +2070,52 @@ version = "0.13.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b5e6043086bf7973472e0c7dff2142ea0b680d30e18d9cc40f267efbf222bd47"
 dependencies = [
- "base16ct",
+ "base16ct 0.2.0",
- "crypto-bigint",
+ "crypto-bigint 0.5.5",
  "digest 0.10.7",
- "ff",
+ "ff 0.13.1",
- "generic-array",
+ "generic-array 0.14.7",
- "group",
+ "group 0.13.0",
  "pkcs8 0.10.2",
  "rand_core 0.6.4",
- "sec1",
+ "sec1 0.7.3",
- "serdect",
+ "serdect 0.2.0",
  "subtle",
  "zeroize",
 ]
 
+[[package]]
+name = "elliptic-curve"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d65aa39b3a5c1c9c1b745c9a019234bb7a21b77abcb4f4d266d706e2d577d65"
+dependencies = [
+ "base16ct 1.0.0",
+ "crypto-bigint 0.7.5",
+ "crypto-common 0.2.1",
+ "ff 0.14.0",
+ "group 0.14.0",
+ "hybrid-array",
+ "pkcs8 0.11.0",
+ "rand_core 0.10.1",
+ "sec1 0.8.1",
+ "serdect 0.4.3",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "elliptic-curve-tools"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a0d5e534f103b079a71ef1d66c6e62c89413f1b62709ca11f744429b4afe5b4"
+dependencies = [
+ "elliptic-curve 0.14.1",
+ "heapless",
+ "serde",
+ "serdect 0.4.3",
+]
+
 [[package]]
 name = "enum-ordinalize"
 version = "4.3.2"
@@ -2127,6 +2190,16 @@ dependencies = [
  "subtle",
 ]
 
+[[package]]
+name = "ff"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1f686ab92a9fb0eaf188f6c6c87b89490baa6fdb0db4544ba4dc47f7942489f"
+dependencies = [
+ "rand_core 0.10.1",
+ "subtle",
+]
+
 [[package]]
 name = "fiat-crypto"
 version = "0.2.9"
@@ -2323,6 +2396,17 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "generic-array"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb130435a959a8d525e6bca66ff6c40981a300ee96d70e3ef56f046556d614a3"
+dependencies = [
+ "rustversion",
+ "serde_core",
+ "typenum",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.2.17"
@@ -2382,11 +2466,22 @@ version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0f9ef7462f7c099f518d754361858f86d8a07af53ba9af0fe635bbccb151a63"
 dependencies = [
- "ff",
+ "ff 0.13.1",
  "rand_core 0.6.4",
  "subtle",
 ]
 
+[[package]]
+name = "group"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fd1a1c7a5206c5b7a3f5a0d7ccd3ff85d0c8f5133d62a02680255b0004af5f4"
+dependencies = [
+ "ff 0.14.0",
+ "rand_core 0.10.1",
+ "subtle",
+]
+
 [[package]]
 name = "h2"
 version = "0.4.13"
@@ -2406,6 +2501,15 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "hash32"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47d60b12902ba28e2730cd37e95b8c9223af2808df9e902d4df49588d1470606"
+dependencies = [
+ "byteorder",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -2446,6 +2550,16 @@ version = "0.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4f467dd6dccf739c208452f8014c75c18bb8301b050ad1cfb27153803edb0f51"
 
+[[package]]
+name = "heapless"
+version = "0.9.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25ba4bd83f9415b58b4ed8dc5714c76e626a105be4646c02630ad730ad3b5aa4"
+dependencies = [
+ "hash32",
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "heck"
 version = "0.5.0"
@@ -2538,11 +2652,13 @@ checksum = "df3b46402a9d5adb4c86a0cf463f42e19994e3ee891101b1841f30a545cb49a9"
 
 [[package]]
 name = "hybrid-array"
-version = "0.4.11"
+version = "0.4.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08d46837a0ed51fe95bd3b05de33cd64a1ee88fc797477ca48446872504507c5"
+checksum = "27f864f10dfb56725ce5ce5472bc52252c8f93a4ab86327122cebf62c5f59a17"
 dependencies = [
  "ctutils",
+ "serde",
+ "subtle",
  "typenum",
  "zeroize",
 ]
@@ -2808,7 +2924,7 @@ version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "879f10e63c20629ecabbb64a8010319738c66a5cd0c29b02d63d272b03751d01"
 dependencies = [
- "generic-array",
+ "generic-array 0.14.7",
 ]
 
 [[package]]
@@ -2945,17 +3061,17 @@ checksum = "f6e3919bbaa2945715f0bb6d3934a173d1e9a59ac23767fbaaef277265a7411b"
 dependencies = [
  "cfg-if",
  "ecdsa",
- "elliptic-curve",
+ "elliptic-curve 0.13.8",
  "once_cell",
- "serdect",
+ "serdect 0.2.0",
  "sha2 0.10.9",
  "signature 2.2.0",
 ]
 
 [[package]]
 name = "kameo"
-version = "0.20.0"
+version = "0.22.2"
-source = "git+https://github.com/hdbg/kameo.git?rev=805b417#805b41783fe90b54827ecad142b422c7a9b69b9a"
+source = "git+https://github.com/hdbg/kameo.git?rev=3bbebac#3bbebac9f2a943be75588d80826e6bea45079d5f"
 dependencies = [
  "downcast-rs",
  "dyn-clone",
@@ -2968,8 +3084,8 @@ dependencies = [
 
 [[package]]
 name = "kameo_actors"
-version = "0.5.0"
+version = "0.8.1"
-source = "git+https://github.com/hdbg/kameo.git?rev=805b417#805b41783fe90b54827ecad142b422c7a9b69b9a"
+source = "git+https://github.com/hdbg/kameo.git?rev=3bbebac#3bbebac9f2a943be75588d80826e6bea45079d5f"
 dependencies = [
  "futures",
  "glob",
@@ -2980,14 +3096,13 @@ dependencies = [
 
 [[package]]
 name = "kameo_macros"
-version = "0.20.0"
+version = "0.21.1"
-source = "git+https://github.com/hdbg/kameo.git?rev=805b417#805b41783fe90b54827ecad142b422c7a9b69b9a"
+source = "git+https://github.com/hdbg/kameo.git?rev=3bbebac#3bbebac9f2a943be75588d80826e6bea45079d5f"
 dependencies = [
- "darling 0.23.0",
  "heck",
  "proc-macro2",
  "quote",
- "syn 2.0.117",
+ "syn 3.0.5",
 ]
 
 [[package]]
@@ -3331,6 +3446,17 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "num-bigint"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93e7820bc0a80a0238e650327316f929ba18d5be054b647490a3a6a339f3e7c0"
+dependencies = [
+ "num-integer",
+ "num-traits",
+ "serde",
+]
+
 [[package]]
 name = "num-conv"
 version = "0.2.1"
@@ -4225,7 +4351,7 @@ dependencies = [
  "bytes",
  "fastrlp 0.3.1",
  "fastrlp 0.4.0",
- "num-bigint",
+ "num-bigint 0.4.6",
  "num-integer",
  "num-traits",
  "parity-scale-codec",
@@ -4452,11 +4578,26 @@ version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3e97a565f76233a6003f9f5c54be1d9c5bdfa3eccfb189469f11ec4901c47dc"
 dependencies = [
- "base16ct",
+ "base16ct 0.2.0",
  "der 0.7.10",
- "generic-array",
+ "generic-array 0.14.7",
  "pkcs8 0.10.2",
- "serdect",
+ "serdect 0.2.0",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "sec1"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d56d437c2f19203ce5f7122e507831de96f3d2d4d3be5af44a0b0a09d8a80e4d"
+dependencies = [
+ "base16ct 1.0.0",
+ "ctutils",
+ "der 0.8.0",
+ "hybrid-array",
+ "serdect 0.4.3",
  "subtle",
  "zeroize",
 ]
@@ -4618,7 +4759,17 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a84f14a19e9a014bb9f4512488d9829a68e04ecabffb0f9904cd1ace94598177"
 dependencies = [
- "base16ct",
+ "base16ct 0.2.0",
+ "serde",
+]
+
+[[package]]
+name = "serdect"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66cf8fedced2fcf12406bcb34223dffb92eaf34908ede12fed414c82b7f00b3e"
+dependencies = [
+ "base16ct 1.0.0",
  "serde",
 ]
 
@@ -4664,6 +4815,17 @@ dependencies = [
  "keccak 0.2.0",
 ]
 
+[[package]]
+name = "sha3"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc9bad02c26382724b2d2692c6f179285e4b54eeecd7968f52a50059c3c11759"
+dependencies = [
+ "digest 0.11.2",
+ "keccak 0.2.0",
+ "sponge-cursor",
+]
+
 [[package]]
 name = "sha3-asm"
 version = "0.1.6"
@@ -4674,6 +4836,17 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "shake"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09057cb2149ad4cbd2da1e26b351f9a4c354219421229c69c3063e6f61947c4a"
+dependencies = [
+ "digest 0.11.2",
+ "keccak 0.2.0",
+ "sponge-cursor",
+]
+
 [[package]]
 name = "sharded-slab"
 version = "0.1.7"
@@ -4807,6 +4980,12 @@ dependencies = [
  "der 0.8.0",
 ]
 
+[[package]]
+name = "sponge-cursor"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a0219bd7d979d58245a4f41f695e1ac9f8befdffadd7f61f1bae9e39abc6620"
+
 [[package]]
 name = "sqlite-wasm-rs"
 version = "0.5.3"
@@ -4934,6 +5113,17 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "syn"
+version = "3.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "12df2e0110f65b775f769bb17ef989067a1d931b2eb822bd4346631eeada89f9"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "syn-solidity"
 version = "1.5.7"
@@ -5574,6 +5764,29 @@ version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
+[[package]]
+name = "vsss-rs"
+version = "6.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6bfc736cfd88115aedb95ba84bc2d428fe351e92a56f69fce090af301402d91"
+dependencies = [
+ "crypto-bigint 0.7.5",
+ "elliptic-curve 0.14.1",
+ "elliptic-curve-tools",
+ "ff 0.14.0",
+ "generic-array 1.4.2",
+ "hex",
+ "hybrid-array",
+ "num-bigint 0.5.1",
+ "num-traits",
+ "rand_core 0.10.1",
+ "serde",
+ "sha3 0.12.0",
+ "shake",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "wait-timeout"
 version = "0.2.1"
@@ -6261,18 +6474,18 @@ dependencies = [
 
 [[package]]
 name = "zeroize"
-version = "1.8.2"
+version = "1.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"
+checksum = "e13c156562582aa81c60cb29407084cdb54c4164760106ab78e6c5b0858cf64e"
 dependencies = [
  "zeroize_derive",
 ]
 
 [[package]]
 name = "zeroize_derive"
-version = "1.4.3"
+version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85a5b4158499876c763cb03bc4e49185d3cccbabb15b33c627f7884f43db852e"
+checksum = "3c50655cbb0fe3fc43170059e702f1ce5e19b84cec58dc87b037a09935c2f328"
 dependencies = [
  "proc-macro2",
  "quote",

server/Cargo.toml

@@ -12,8 +12,8 @@ base64 = "0.22.1"
 chrono = { version = "0.4.44", features = ["serde"] }
 futures = "0.3.32"
 k256 = { version = "0.13.4", features = ["ecdsa", "pkcs8"] }
-kameo = {git = "https://github.com/hdbg/kameo.git", rev = "805b417"}
+kameo = {git = "https://github.com/hdbg/kameo.git", rev = "3bbebac"}
-kameo_actors = {git = "https://github.com/hdbg/kameo.git", rev = "805b417"}
+kameo_actors = {git = "https://github.com/hdbg/kameo.git", rev = "3bbebac"}
 hmac = "0.13.0"
 miette = { version = "7.6.0", features = ["fancy", "serde"] }
 ml-dsa = { version = "0.1.0-rc.9", features = ["zeroize"] }
@@ -21,6 +21,7 @@ mutants = "0.0.4"
 prost = "0.14.3"
 prost-types = { version = "0.14.3", features = ["chrono"] }
 rand = "0.10.1"
+rand_core = "0.10.1"
 rcgen = { version = "0.14.7", features = [ "aws_lc_rs",  "pem", "x509-parser", "zeroize" ], default-features = false }
 rstest = "0.26.1"
 rustls = { version = "0.23.40", features = ["aws-lc-rs", "logging", "prefer-post-quantum", "std"], default-features = false }
@@ -76,6 +77,8 @@ needless_pass_by_ref_mut = "allow"
 pub_underscore_fields = "allow"
 redundant_pub_crate = "allow" 
 uninhabited_references = "allow" # safe with unsafe_code = "forbid" and standard uninhabited pattern (match *self {})
+too-many-lines = "allow" # this is a very common pattern in server code, and it's not always possible to break it down into smaller modules without hurting readability
+unused_async_trait_impl = "allow" # too pedantic
 
 # restriction lints
 alloc_instead_of_core = "warn"

server/crates/arbiter-client/src/auth.rs

@@ -100,7 +100,7 @@ async fn send_auth_challenge_solution(
     key: &SigningKey,
     challenge: AuthChallenge,
 ) -> Result<(), AuthError> {
-    let timestamp = DateTime::from_timestamp_nanos(challenge.timestamp_nanos as i64);
+    let timestamp = DateTime::from_timestamp_nanos(challenge.timestamp_nanos.cast_signed());
     let challenge = authn::AuthChallenge {
         nonce: *challenge
             .random

server/crates/arbiter-client/src/client.rs

@@ -94,7 +94,6 @@ impl ArbiterClient {
     }
 
     #[cfg(feature = "evm")]
-    #[expect(clippy::unused_async, reason = "false positive")]
     pub async fn evm_wallets(&self) -> Result<Vec<ArbiterEvmWallet>, ArbiterClientError> {
         todo!("fetch EVM wallet list from server")
     }

server/crates/arbiter-proto/src/lib.rs

@@ -23,6 +23,10 @@ pub mod proto {
             tonic::include_proto!("arbiter.operator.evm");
         }
 
+        pub mod governance {
+            tonic::include_proto!("arbiter.operator.governance");
+        }
+
         pub mod sdk_client {
             tonic::include_proto!("arbiter.operator.sdk_client");
         }
@@ -34,6 +38,10 @@ pub mod proto {
                 tonic::include_proto!("arbiter.operator.vault.bootstrap");
             }
 
+            pub mod rekey {
+                tonic::include_proto!("arbiter.operator.vault.rekey");
+            }
+
             pub mod unseal {
                 tonic::include_proto!("arbiter.operator.vault.unseal");
             }

server/crates/arbiter-server/Cargo.toml

@@ -31,6 +31,7 @@ diesel_migrations = { version = "2.3.2", features = ["sqlite"] }
 async-trait.workspace = true
 tokio-stream.workspace = true
 rand.workspace = true
+rand_core.workspace = true
 rcgen.workspace = true
 chrono.workspace = true
 kameo.workspace = true
@@ -50,6 +51,7 @@ subtle = "2.6.1"
 x25519-dalek.workspace = true
 k256.workspace = true
 kameo_actors.workspace = true
+vsss-rs = "6.0.1"
 
 [dev-dependencies]
 proptest = "1.11.0"

server/crates/arbiter-server/migrations/2026-02-14-171124-0000_init/up.sql

@@ -37,7 +37,8 @@ create table if not exists tls_history (
 create table if not exists arbiter_settings (
     id INTEGER not null PRIMARY KEY CHECK (id = 1), -- singleton row, id must be 1
     root_key_id integer references root_key_history (id) on delete RESTRICT, -- if null, means wasn't bootstrapped yet
-    tls_id integer references tls_history (id) on delete RESTRICT
+    tls_id integer references tls_history (id) on delete RESTRICT,
+    shamir_threshold integer
 ) STRICT;
 
 insert into arbiter_settings (id) values (1) on conflict do nothing;
@@ -56,6 +57,7 @@ create table if not exists operator (
 
     share blob not null,
     share_nonce blob not null,
+    share_salt blob not null,
 
     created_at integer not null default(unixepoch ('now')),
     updated_at integer not null default(unixepoch ('now'))

server/crates/arbiter-server/src/actors/bootstrap.rs

@@ -1,98 +1,164 @@
-use crate::db::{self, DatabasePool, schema};
+use crate::{
+    actors::vault::events,
+    db::{self, schema},
+};
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_proto::{BOOTSTRAP_PATH, home_path};
 
 use diesel::QueryDsl;
 use diesel_async::RunQueryDsl;
-use kameo::{Actor, messages};
+use kameo::{
-use rand::{RngExt, distr::Alphanumeric, make_rng, rngs::StdRng};
+    Actor,
+    actor::ActorRef,
+    messages,
+    prelude::{Context, Message},
+};
+use kameo_actors::message_bus::{MessageBus, Register};
+use rand::{RngExt, distr::Alphanumeric, rngs::SysRng};
+use rand_core::UnwrapErr;
+use std::path::{Path, PathBuf};
 use subtle::ConstantTimeEq as _;
-use thiserror::Error;
+use tracing::warn;
 
 const TOKEN_LENGTH: usize = 64;
 
-pub async fn generate_token() -> Result<String, std::io::Error> {
+async fn write_token_file(path: &Path, content: &str) -> Result<(), std::io::Error> {
-    let rng: StdRng = make_rng();
+    if let Some(parent) = path.parent() {
-
+        tokio::fs::create_dir_all(parent).await?;
-    let token = rng.sample_iter(Alphanumeric).take(TOKEN_LENGTH).fold(
+    }
-        String::default(),
+    tokio::fs::write(path, content.as_bytes()).await?;
-        |mut accum, char| {
+    #[cfg(unix)]
-            accum += char.to_string().as_str();
+    {
-            accum
+        use std::os::unix::fs::PermissionsExt as _;
-        },
+        tokio::fs::set_permissions(path, std::fs::Permissions::from_mode(0o600)).await?;
-    );
+    }
-
+    Ok(())
-    tokio::fs::write(home_path()?.join(BOOTSTRAP_PATH), token.as_str()).await?;
-
-    Ok(token)
 }
 
-#[derive(Error, Debug)]
+async fn remove_token_file(path: &Path) {
+    match tokio::fs::remove_file(path).await {
+        Ok(()) => {}
+        Err(error) if error.kind() == std::io::ErrorKind::NotFound => {}
+        Err(error) => warn!(?error, ?path, "Failed to remove bootstrap token file"),
+    }
+}
+
+async fn generate_token(path: &Path) -> Result<SafeCell<[u8; TOKEN_LENGTH]>, std::io::Error> {
+    let mut cell = SafeCell::new([0u8; TOKEN_LENGTH]);
+    {
+        let mut buf = cell.write();
+        for (slot, byte) in buf
+            .iter_mut()
+            .zip(UnwrapErr(SysRng).sample_iter(Alphanumeric))
+        {
+            *slot = byte;
+        }
+    }
+    let token = cell.read_inline(|buf| String::from_utf8_lossy(buf.as_ref()).into_owned());
+    write_token_file(path, &token).await?;
+    Ok(cell)
+}
+
+#[derive(Debug, thiserror::Error)]
 pub enum Error {
     #[error("Database error: {0}")]
     Database(#[from] db::PoolError),
-
     #[error("I/O error: {0}")]
     Io(#[from] std::io::Error),
-
     #[error("Database query error: {0}")]
     Query(#[from] diesel::result::Error),
 }
 
-#[derive(Actor)]
+/// Custodian of the one-time bootstrap token.
+///
+/// The token authorises registering operator identities before the vault
+/// exists. A Shamir committee needs every member registered before it can be
+/// declared, so the token stays valid across several registrations and is
+/// retired by the `Bootstrapped` event rather than by first use, whichever
+/// bootstrap path fired it.
+///
+/// Every daemon start mints a fresh token and overwrites the file: a token
+/// handed out by an earlier run is dead.
 pub struct Bootstrapper {
-    token: Option<String>,
+    token: Option<SafeCell<[u8; TOKEN_LENGTH]>>,
+    token_path: Option<PathBuf>,
+    events: ActorRef<MessageBus>,
+}
+
+impl Actor for Bootstrapper {
+    type Args = Self;
+    type Error = std::convert::Infallible;
+
+    async fn on_start(args: Self::Args, actor_ref: ActorRef<Self>) -> Result<Self, Self::Error> {
+        let _ = args
+            .events
+            .tell(Register(actor_ref.recipient::<events::Bootstrapped>()))
+            .await;
+        Ok(args)
+    }
 }
 
 impl Bootstrapper {
-    pub async fn new(db: &DatabasePool) -> Result<Self, Error> {
+    pub async fn new(db: &db::DatabasePool, events: ActorRef<MessageBus>) -> Result<Self, Error> {
-        let row_count: i64 = {
+        let path = home_path()?.join(BOOTSTRAP_PATH);
         let mut conn = db.get().await?;
 
-            schema::operator::table
+        let bootstrapped = schema::arbiter_settings::table
-                .count()
+            .select(schema::arbiter_settings::root_key_id)
-                .get_result(&mut conn)
+            .first::<Option<i32>>(&mut conn)
             .await?
-        };
+            .is_some();
+        if bootstrapped {
+            // A token file can outlive the bootstrap that made it obsolete:
+            // the daemon may have been killed before the event was handled.
+            remove_token_file(&path).await;
+            return Ok(Self {
+                token: None,
+                token_path: None,
+                events,
+            });
+        }
 
-        let token = if row_count == 0 {
+        Ok(Self {
-            let token = generate_token().await?;
+            token: Some(generate_token(&path).await?),
-            Some(token)
+            token_path: Some(path),
-        } else {
+            events,
-            None
+        })
-        };
+    }
 
-        Ok(Self { token })
+    async fn forget(&mut self) {
+        self.token = None;
+        if let Some(path) = self.token_path.take() {
+            remove_token_file(&path).await;
+        }
+    }
+}
+
+impl Message<events::Bootstrapped> for Bootstrapper {
+    type Reply = ();
+
+    async fn handle(
+        &mut self,
+        _: events::Bootstrapped,
+        _ctx: &mut Context<Self, Self::Reply>,
+    ) -> Self::Reply {
+        self.forget().await;
     }
 }
     
 #[messages]
 impl Bootstrapper {
     #[message]
-    pub fn is_correct_token(&self, token: String) -> bool {
+    pub fn verify_token(&mut self, token: Vec<u8>) -> bool {
-        self.token.as_ref().is_some_and(|expected| {
+        self.token.as_mut().is_some_and(|expected| {
-            let expected_bytes = expected.as_bytes();
+            expected.read_inline(|bytes| bool::from(bytes.as_ref().ct_eq(token.as_slice())))
-            let token_bytes = token.as_bytes();
-
-            let choice = expected_bytes.ct_eq(token_bytes);
-            bool::from(choice)
         })
     }
 
     #[message]
-    pub fn consume_token(&mut self, token: String) -> bool {
+    pub fn get_token(&mut self) -> Option<String> {
-        if self.is_correct_token(token) {
+        self.token
-            self.token = None;
+            .as_mut()
-            true
+            .map(|cell| cell.read_inline(|buf| String::from_utf8_lossy(buf.as_ref()).into_owned()))
-        } else {
-            false
-        }
-    }
-}
-
-#[messages]
-impl Bootstrapper {
-    #[message]
-    pub fn get_token(&self) -> Option<String> {
-        self.token.clone()
     }
 }

server/crates/arbiter-server/src/actors/evm/mod.rs

@@ -1,6 +1,6 @@
 use crate::{
     actors::vault::{CreateNew, Decrypt, Vault},
-    crypto::integrity,
+    crypto::integrity::{self, Integrable},
     db::{
         DatabaseError, DatabasePool,
         models::{self, EvmWalletId},
@@ -25,14 +25,35 @@ use diesel::{
 use diesel_async::RunQueryDsl;
 use kameo::{Actor, actor::ActorRef, messages};
 use rand::{SeedableRng, rng, rngs::StdRng};
+use tracing::error;
 
 pub use crate::evm::safe_signer;
 
+/// Integrity guard that binds a wallet's encrypted key ID to its Ethereum address.
+/// Both fields are included in the HMAC — swapping `aead_encrypted_id` in the DB
+/// invalidates the envelope MAC, and the AEAD ciphertext is also bound to `address`
+/// as AAD, so decryption fails too.
+#[derive(arbiter_macros::Hashable)]
+struct EvmWalletIntegrity {
+    aead_encrypted_id: i32,
+    address: Address,
+}
+
+impl Integrable for EvmWalletIntegrity {
+    const KIND: &'static str = "evm_wallet";
+}
+
 #[derive(Debug, thiserror::Error)]
 pub enum SignTransactionError {
     #[error("Wallet not found")]
     WalletNotFound,
 
+    #[error("Decrypted key does not match requested wallet address")]
+    KeyAddressMismatch,
+
+    #[error("Internal signing error")]
+    Internal,
+
     #[error("Database error: {0}")]
     Database(#[from] DatabaseError),
 
@@ -64,6 +85,12 @@ pub enum Error {
     Integrity(#[from] integrity::Error),
 }
 
+impl From<diesel::result::Error> for Error {
+    fn from(e: diesel::result::Error) -> Self {
+        Self::Database(DatabaseError::from(e))
+    }
+}
+
 #[derive(Actor)]
 pub struct EvmActor {
     pub vault: ActorRef<Vault>,
@@ -97,20 +124,39 @@ impl EvmActor {
 
         let aead_id: i32 = self
             .vault
-            .ask(CreateNew { plaintext })
+            .ask(CreateNew {
+                plaintext,
+                aad: address.as_slice().to_vec(),
+            })
             .await
             .map_err(|_| Error::VaultSend)?;
 
         let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
-        let wallet_id = insert_into(schema::evm_wallet::table)
+        let wallet_id = conn
+            .exclusive_transaction(async |conn| {
+                let wallet_id: i32 = insert_into(schema::evm_wallet::table)
                     .values(&models::NewEvmWallet {
                         address: address.as_slice().to_vec(),
                         aead_encrypted_id: aead_id,
                     })
                     .returning(schema::evm_wallet::id)
-            .get_result(&mut conn)
+                    .get_result(conn)
                     .await
-            .map_err(DatabaseError::from)?;
+                    .map_err(DatabaseError::from)
+                    .map_err(Error::Database)?;
+
+                integrity::sign_entity(
+                    conn,
+                    &self.vault,
+                    &EvmWalletIntegrity { address, aead_encrypted_id: aead_id },
+                    wallet_id,
+                )
+                .await
+                .map_err(Error::Integrity)?;
+
+                Ok::<i32, Error>(wallet_id)
+            })
+            .await?;
 
         Ok((wallet_id, address))
     }
@@ -160,29 +206,14 @@ impl EvmActor {
     }
 
     #[message]
-    #[expect(clippy::unused_async, reason = "reserved for impl")]
+    pub async fn useragent_delete_grant(
-    pub async fn operator_delete_grant(&mut self, _grant_id: i32) -> Result<(), Error> {
+        &mut self,
-        // let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        grant_id: i32,
-        // let vault = self.vault.clone();
+    ) -> Result<(), Error> {
-
+        self.engine
-        // diesel_async::AsyncConnection::transaction(&mut conn, |conn| {
+            .revoke_grant(grant_id)
-        //     Box::pin(async move {
+            .await
-        //         diesel::update(schema::evm_basic_grant::table)
+            .map_err(Error::from)
-        //             .filter(schema::evm_basic_grant::id.eq(grant_id))
-        //             .set(schema::evm_basic_grant::revoked_at.eq(SqliteTimestamp::now()))
-        //             .execute(conn)
-        //             .await?;
-
-        //         let signed = integrity::evm::load_signed_grant_by_basic_id(conn, grant_id).await?;
-
-        //         diesel::result::QueryResult::Ok(())
-        //     })
-        // })
-        // .await
-        // .map_err(DatabaseError::from)?;
-
-        // Ok(())
-        todo!()
     }
 
     #[message]
@@ -256,16 +287,51 @@ impl EvmActor {
             .ok_or(SignTransactionError::WalletNotFound)?;
         drop(conn);
 
+        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        let attestation = integrity::verify_entity(
+            &mut conn,
+            &self.vault,
+            &EvmWalletIntegrity {
+                address: wallet_address,
+                aead_encrypted_id: wallet.aead_encrypted_id,
+            },
+            wallet.id.to_raw(),
+        )
+        .await
+        .map_err(|e| {
+            error!(?e, ?wallet.id, "EVM wallet integrity check failed");
+            SignTransactionError::Internal
+        })?;
+        drop(conn);
+
+        if attestation != integrity::AttestationStatus::Attested {
+            error!(
+                ?wallet.id,
+                "EVM wallet integrity unavailable; refusing to sign"
+            );
+            return Err(SignTransactionError::Internal);
+        }
+
         let raw_key: SafeCell<Vec<u8>> = self
             .vault
             .ask(Decrypt {
                 aead_id: wallet.aead_encrypted_id,
+                aad: wallet.address.clone(),
             })
             .await
             .map_err(|_| SignTransactionError::VaultSend)?;
 
         let signer = safe_signer::SafeSigner::from_cell(raw_key)?;
 
+        if signer.address() != wallet_address {
+            error!(
+                expected = %wallet_address,
+                actual = %signer.address(),
+                "Decrypted private key address does not match requested wallet"
+            );
+            return Err(SignTransactionError::KeyAddressMismatch);
+        }
+
         self.engine
             .evaluate_transaction(wallet_access, transaction.clone(), RunKind::Execution)
             .await?;

server/crates/arbiter-server/src/actors/flow_coordinator/client_connect_approval.rs

@@ -11,7 +11,9 @@ use kameo::{
     prelude::{ActorId, ActorRef, ActorStopReason, Context, WeakActorRef},
     reply::ReplySender,
 };
-use std::ops::ControlFlow;
+use std::{ops::ControlFlow, time::Duration};
+
+const APPROVAL_TIMEOUT: Duration = Duration::from_secs(30);
 
 pub struct Args {
     pub client: ClientProfile,
@@ -64,6 +66,14 @@ impl Actor for ClientApprovalController {
                 .await;
         }
 
+        let weak = actor_ref.downgrade();
+        tokio::spawn(async move {
+            tokio::time::sleep(APPROVAL_TIMEOUT).await;
+            if let Some(r) = weak.upgrade() {
+                let _ = r.tell(OnApprovalTimeout {}).await;
+            }
+        });
+
         Ok(this)
     }
 
@@ -104,4 +114,14 @@ impl ClientApprovalController {
             ctx.stop();
         }
     }
+
+    /// Fired after `APPROVAL_TIMEOUT` elapses. Any operator that hasn't responded
+    /// by then is treated as a denial to prevent zombie sessions from blocking the flow.
+    #[message(ctx)]
+    pub fn on_approval_timeout(&mut self, ctx: &mut Context<Self, ()>) {
+        if self.pending > 0 {
+            self.send_reply(Ok(false));
+            ctx.stop();
+        }
+    }
 }

server/crates/arbiter-server/src/actors/flow_coordinator/mod.rs

@@ -20,6 +20,8 @@ pub mod client_connect_approval;
 
 pub struct FlowCoordinator {
     pub clients: HashMap<ActorId, ActorRef<ClientSession>>,
+    /// Maps DB `client_id` → `ActorId` for fast connected-client lookup.
+    client_ids: HashMap<i32, ActorId>,
     operator_registry: ActorRef<OperatorRegistry>,
 }
 
@@ -27,6 +29,7 @@ impl FlowCoordinator {
     pub fn new(operator_registry: ActorRef<OperatorRegistry>) -> Self {
         Self {
             clients: HashMap::default(),
+            client_ids: HashMap::default(),
             operator_registry,
         }
     }
@@ -48,6 +51,7 @@ impl Actor for FlowCoordinator {
         _: ActorStopReason,
     ) -> Result<ControlFlow<ActorStopReason>, Self::Error> {
         if self.clients.remove(&id).is_some() {
+            self.client_ids.retain(|_, actor_id| *actor_id != id);
             info!(
                 ?id,
                 actor = "FlowCoordinator",
@@ -75,14 +79,28 @@ impl FlowCoordinator {
     #[message(ctx)]
     pub async fn register_client(
         &mut self,
+        client_id: i32,
         actor: ActorRef<ClientSession>,
         ctx: &mut Context<Self, ()>,
     ) {
-        info!(id = %actor.id(), actor = "FlowCoordinator", event = "client.connected");
+        info!(id = %actor.id(), client_id, actor = "FlowCoordinator", event = "client.connected");
         ctx.actor_ref().link(&actor).await;
+        self.client_ids.insert(client_id, actor.id());
         self.clients.insert(actor.id(), actor);
     }
 
+    #[message]
+    pub fn is_client_connected(&self, client_id: i32) -> bool {
+        self.client_ids.contains_key(&client_id)
+    }
+
+    /// Returns the DB `client_ids` of all currently connected SDK clients.
+    /// Used by operator sessions on startup to seed their approved-client set.
+    #[message]
+    pub fn get_connected_client_ids(&self) -> Vec<i32> {
+        self.client_ids.keys().copied().collect()
+    }
+
     #[message(ctx)]
     pub async fn request_client_approval(
         &mut self,

server/crates/arbiter-server/src/actors/mod.rs

@@ -1,7 +1,7 @@
 use crate::{
     actors::{
         bootstrap::Bootstrapper, evm::EvmActor, flow_coordinator::FlowCoordinator,
-        operator_registry::OperatorRegistry, vault::Vault,
+        operator_registry::OperatorRegistry, vault::Vault, vault_coordinator::VaultCoordinator,
     },
     db,
 };
@@ -15,20 +15,22 @@ pub mod evm;
 pub mod flow_coordinator;
 pub mod operator_registry;
 pub mod vault;
+pub mod vault_coordinator;
 
 #[derive(Error, Debug)]
 pub enum SpawnError {
     #[error("Failed to spawn Bootstrapper actor")]
     Bootstrapper(#[from] bootstrap::Error),
-
     #[error("Failed to spawn Vault actor")]
     Vault(#[from] vault::Error),
+    #[error("Failed to spawn VaultCoordinator actor")]
+    VaultCoordinator(#[from] vault_coordinator::Error),
 }
 
-/// Long-lived actors that are shared across all connections and handle global state and operations
 #[derive(Clone)]
 pub struct GlobalActors {
     pub vault: ActorRef<Vault>,
+    pub vault_coordinator: ActorRef<VaultCoordinator>,
     pub bootstrapper: ActorRef<Bootstrapper>,
     pub flow_coordinator: ActorRef<FlowCoordinator>,
     pub operator_registry: ActorRef<OperatorRegistry>,
@@ -42,18 +44,22 @@ impl GlobalActors {
     }
 
     pub async fn spawn(db: db::DatabasePool) -> Result<Self, SpawnError> {
-        let message_bus = Self::spawn_message_bus();
+        let events = Self::spawn_message_bus();
-        let key_holder = Vault::spawn(Vault::new(db.clone(), message_bus.clone()).await?);
+        let vault = Vault::spawn(Vault::new(db.clone(), events.clone()).await?);
+        let bootstrapper = Bootstrapper::spawn(Bootstrapper::new(&db, events.clone()).await?);
+        let vault_coordinator =
+            VaultCoordinator::spawn(VaultCoordinator::new(db.clone(), vault.clone()));
         let operator_registry = OperatorRegistry::spawn(OperatorRegistry::default());
         Ok(Self {
-            bootstrapper: Bootstrapper::spawn(Bootstrapper::new(&db).await?),
+            bootstrapper,
-            evm: EvmActor::spawn(EvmActor::new(key_holder.clone(), db)),
+            evm: EvmActor::spawn(EvmActor::new(vault.clone(), db.clone())),
-            vault: key_holder,
+            vault,
+            vault_coordinator,
             flow_coordinator: FlowCoordinator::spawn(FlowCoordinator::new(
                 operator_registry.clone(),
             )),
             operator_registry,
-            events: message_bus,
+            events,
         })
     }
 }

server/crates/arbiter-server/src/actors/operator_registry.rs

@@ -20,8 +20,8 @@ impl Actor for OperatorRegistry {
 
     type Error = Infallible;
 
-    async fn on_start(args: Self::Args, _: ActorRef<Self>) -> Result<Self, Self::Error> {
+    fn on_start(args: Self::Args, _: ActorRef<Self>) -> impl Future<Output = Result<Self, Self::Error>> {
-        Ok(args)
+        std::future::ready(Ok(args))
     }
 
     async fn on_link_died(

server/crates/arbiter-server/src/actors/vault/mod.rs

@@ -1,15 +1,17 @@
 use crate::{
     crypto::{
-        KeyCell, derive_key,
+        KeyCell,
         encryption::v1::{self, Nonce},
         integrity::v1::HmacSha256,
     },
     db::{
         self,
+        custody::{self, CustodyRecord},
         models::{self, RootKeyHistory, RootKeyHistoryId},
         schema::{self},
     },
 };
+
 use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 
 use chrono::Utc;
@@ -22,7 +24,7 @@ use hmac::{KeyInit as _, Mac as _};
 use kameo::{Actor, Reply, actor::ActorRef, messages};
 use kameo_actors::message_bus::{MessageBus, Publish};
 use strum::{EnumDiscriminants, IntoDiscriminant};
-use tracing::{error, info};
+use tracing::{error, info, warn};
 
 pub mod events {
     #[derive(Clone, Copy)]
@@ -45,6 +47,8 @@ pub enum Error {
     Sealed,
     #[error("Invalid key provided")]
     InvalidKey,
+    #[error("Vault locked: too many failed unseal attempts")]
+    LockedOut,
 
     #[error("Requested aead entry not found")]
     NotFound,
@@ -58,8 +62,14 @@ pub enum Error {
     #[error("Database transaction error: {0}")]
     DatabaseTransaction(#[from] diesel::result::Error),
 
+    #[error("Custody storage error: {0}")]
+    Custody(#[from] custody::Error),
+
     #[error("Broken database")]
     BrokenDatabase,
+
+    #[error("Integrity key version mismatch: envelope uses key {envelope:?}, current key is {current:?}")]
+    KeyVersionMismatch { envelope: RootKeyHistoryId, current: RootKeyHistoryId },
 }
 
 struct Unsealed {
@@ -79,6 +89,8 @@ enum State {
     Unsealed(Unsealed),
 }
 
+const MAX_UNSEAL_ATTEMPTS: u32 = 5;
+
 /// Manages vault root key and tracks current state of the vault (bootstrapped/unbootstrapped, sealed/unsealed).
 ///
 /// Provides API for encrypting and decrypting data using the vault root key.
@@ -88,6 +100,7 @@ pub struct Vault {
     db: db::DatabasePool,
     state: State,
     events: ActorRef<MessageBus>,
+    unseal_failures: u32,
 }
 
 #[messages]
@@ -110,7 +123,12 @@ impl Vault {
             }
         };
 
-        Ok(Self { db, state, events })
+        Ok(Self {
+            db,
+            state,
+            events,
+            unseal_failures: 0,
+        })
     }
 
     // Exclusive transaction to avoid race condtions if multiple vaults write
@@ -159,13 +177,16 @@ impl Vault {
         }
     }
 
+    /// Create the root key and take the vault into the unsealed state.
     #[message]
-    pub async fn bootstrap(&mut self, seal_key_raw: SafeCell<Vec<u8>>) -> Result<(), Error> {
+    pub async fn bootstrap(
+        &mut self,
+        mut seal_key: KeyCell,
+        custody: Option<CustodyRecord>,
+    ) -> Result<(), Error> {
         if !matches!(self.state, State::Unbootstrapped) {
             return Err(Error::AlreadyBootstrapped);
         }
-        let salt = v1::generate_salt();
-        let mut seal_key = derive_key(seal_key_raw, &salt);
         let mut root_key = KeyCell::new_secure_random();
 
         // Zero nonces are fine because they are one-time
@@ -194,7 +215,7 @@ impl Vault {
                         root_key_encryption_nonce: root_key_nonce.to_vec(),
                         data_encryption_nonce: data_encryption_nonce_bytes.clone(),
                         schema_version: 1,
-                        salt: salt.to_vec(),
+                        salt: v1::generate_salt().to_vec(),
                     })
                     .returning(schema::root_key_history::id)
                     .get_result(&mut *conn)
@@ -205,9 +226,11 @@ impl Vault {
                     .execute(&mut *conn)
                     .await?;
 
-                Result::<_, diesel::result::Error>::Ok(RootKeyHistoryId::from_raw(
+                if let Some(record) = custody.as_ref() {
-                    root_key_history_id,
+                    custody::write_record(&mut *conn, record).await?;
-                ))
+                }
+
+                Result::<_, Error>::Ok(RootKeyHistoryId::from_raw(root_key_history_id))
             })
             .await?;
 
@@ -223,7 +246,11 @@ impl Vault {
     }
 
     #[message]
-    pub async fn try_unseal(&mut self, seal_key_raw: SafeCell<Vec<u8>>) -> Result<(), Error> {
+    pub async fn try_unseal(&mut self, mut seal_key: KeyCell) -> Result<(), Error> {
+        if self.unseal_failures >= MAX_UNSEAL_ATTEMPTS {
+            return Err(Error::LockedOut);
+        }
+
         let State::Sealed {
             root_key_history_id,
         } = &self.state
@@ -241,13 +268,6 @@ impl Vault {
                 .await?
         };
 
-        let salt = &current_key.salt;
-        let salt = v1::Salt::try_from(salt.as_slice()).map_err(|_| {
-            error!("Broken database: invalid salt for root key");
-            Error::BrokenDatabase
-        })?;
-        let mut seal_key = derive_key(seal_key_raw, &salt);
-
         let mut root_key = SafeCell::new(current_key.ciphertext.clone());
 
         let nonce =
@@ -256,13 +276,27 @@ impl Vault {
                 Error::BrokenDatabase
             })?;
 
-        seal_key
+        if seal_key
             .decrypt_in_place(&nonce, v1::ROOT_KEY_TAG, &mut root_key)
-            .map_err(|err| {
+            .is_err()
-                error!(?err, "Failed to unseal root key: invalid seal key");
+        {
-                Error::InvalidKey
+            self.unseal_failures += 1;
-            })?;
+            if self.unseal_failures >= MAX_UNSEAL_ATTEMPTS {
+                error!(
+                    attempts = self.unseal_failures,
+                    "Vault locked: maximum failed unseal attempts reached"
+                );
+            } else {
+                warn!(
+                    attempts = self.unseal_failures,
+                    remaining = MAX_UNSEAL_ATTEMPTS - self.unseal_failures,
+                    "Failed unseal attempt"
+                );
+            }
+            return Err(Error::InvalidKey);
+        }
 
+        self.unseal_failures = 0;
         self.state = State::Unsealed(Unsealed {
             root_key_history_id: current_key.id,
             root_key: KeyCell::try_from(root_key).map_err(|err| {
@@ -277,8 +311,10 @@ impl Vault {
         Ok(())
     }
 
+    /// Decrypts an AEAD entry. The `aad` must match the value used at encryption time;
+    /// a mismatch causes authentication failure, preventing cross-wallet key swaps.
     #[message]
-    pub async fn decrypt(&mut self, aead_id: i32) -> Result<SafeCell<Vec<u8>>, Error> {
+    pub async fn decrypt(&mut self, aead_id: i32, aad: Vec<u8>) -> Result<SafeCell<Vec<u8>>, Error> {
         let Unsealed { root_key, .. } = Self::expect_unsealed(&mut self.state)?;
 
         let row: models::AeadEncrypted = {
@@ -300,13 +336,15 @@ impl Vault {
             Error::BrokenDatabase
         })?;
         let mut output = SafeCell::new(row.ciphertext);
-        root_key.decrypt_in_place(&nonce, v1::TAG, &mut output)?;
+        root_key.decrypt_in_place(&nonce, &aad, &mut output)?;
         Ok(output)
     }
 
+    /// Creates a new `aead_encrypted` entry and returns its ID.
+    /// The `aad` is bound into the ciphertext and must be reproduced exactly at decryption time.
     // Creates new `aead_encrypted` entry in the database and returns it's ID
     #[message]
-    pub async fn create_new(&mut self, mut plaintext: SafeCell<Vec<u8>>) -> Result<i32, Error> {
+    pub async fn create_new(&mut self, mut plaintext: SafeCell<Vec<u8>>, aad: Vec<u8>) -> Result<i32, Error> {
         let Unsealed {
             root_key,
             root_key_history_id,
@@ -318,7 +356,7 @@ impl Vault {
 
         let mut ciphertext_buffer = plaintext.write();
         let ciphertext_buffer: &mut Vec<u8> = ciphertext_buffer.as_mut();
-        root_key.encrypt_in_place(&nonce, v1::TAG, &mut *ciphertext_buffer)?;
+        root_key.encrypt_in_place(&nonce, &aad, &mut *ciphertext_buffer)?;
 
         let ciphertext = std::mem::take(ciphertext_buffer);
 
@@ -354,11 +392,9 @@ impl Vault {
             root_key_history_id,
         } = Self::expect_unsealed(&mut self.state)?;
 
-        let mut hmac = root_key
+        let mut hmac = root_key.0.read_inline(|k| {
-            .0
+            HmacSha256::new_from_slice(k)
-            .read_inline(|k| match HmacSha256::new_from_slice(k) {
+                .unwrap_or_else(|_| unreachable!("HMAC accepts keys of any size"))
-                Ok(v) => v,
-                Err(_) => unreachable!("HMAC accepts keys of any size"),
         });
         hmac.update(&root_key_history_id.to_raw().to_be_bytes());
         hmac.update(&mac_input);
@@ -380,14 +416,15 @@ impl Vault {
         } = Self::expect_unsealed(&mut self.state)?;
 
         if *root_key_history_id != key_version {
-            return Ok(false);
+            return Err(Error::KeyVersionMismatch {
+                envelope: key_version,
+                current: *root_key_history_id,
+            });
         }
 
-        let mut hmac = root_key
+        let mut hmac = root_key.0.read_inline(|k| {
-            .0
+            HmacSha256::new_from_slice(k)
-            .read_inline(|k| match HmacSha256::new_from_slice(k) {
+                .unwrap_or_else(|_| unreachable!("HMAC accepts keys of any size"))
-                Ok(v) => v,
-                Err(_) => unreachable!("HMAC accepts keys of any size"),
         });
         hmac.update(&key_version.to_raw().to_be_bytes());
         hmac.update(&mac_input);
@@ -413,8 +450,6 @@ impl Vault {
 #[cfg(test)]
 mod tests {
     use crate::actors::GlobalActors;
-    use crate::db::models::RootKeyHistory;
-    use arbiter_crypto::safecell::SafeCellHandle as _;
 
     use super::*;
 
@@ -422,8 +457,8 @@ mod tests {
         let mut actor = Vault::new(db.clone(), GlobalActors::spawn_message_bus())
             .await
             .unwrap();
-        let seal_key = SafeCell::new(b"test-seal-key".to_vec());
+        let seal_key = KeyCell::from([0u8; 32]);
-        actor.bootstrap(seal_key).await.unwrap();
+        actor.bootstrap(seal_key, None).await.unwrap();
         actor
     }
 
@@ -432,12 +467,13 @@ mod tests {
     async fn nonce_monotonic_even_when_nonce_allocation_interleaves() {
         let db = db::create_test_pool().await;
         let mut actor = bootstrapped_actor(&db).await;
-        let root_key_history_id = match actor.state {
+
-            State::Unsealed(Unsealed {
+        let State::Unsealed(Unsealed {
             root_key_history_id,
             ..
-            }) => root_key_history_id,
+        }) = actor.state
-            _ => panic!("expected unsealed state"),
+        else {
+            panic!("expected unsealed state")
         };
 
         let n1 = Vault::get_new_nonce(&db, root_key_history_id)
@@ -457,7 +493,7 @@ mod tests {
         assert_eq!(root_row.data_encryption_nonce, n2.to_vec());
 
         let id = actor
-            .create_new(SafeCell::new(b"post-interleave".to_vec()))
+            .create_new(SafeCell::new(b"post-interleave".to_vec()), b"test-aad".to_vec())
             .await
             .unwrap();
         let row: models::AeadEncrypted = schema::aead_encrypted::table

server/crates/arbiter-server/src/actors/vault_coordinator/mod.rs

@@ -0,0 +1,378 @@
+//! Coordinates the multi-operator ceremonies that create and open the vault.
+//!
+//! The coordinator collects one passphrase per committee member, then hands the
+//! assembled material to [`Vault`] in a single message. It owns no Diesel code:
+//! everything it reads or writes goes through [`db::custody`].
+
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+use argon2::RECOMMENDED_SALT_LEN;
+use kameo::{Actor, actor::ActorRef, error::SendError, messages};
+use rand::rngs::SysRng;
+use rand_core::{Rng as _, UnwrapErr};
+
+use crate::{
+    actors::vault::{self, Bootstrap, TryUnseal, Vault},
+    crypto::{KeyCell, derive_key, encryption::v1::Nonce, shamir},
+    db::{
+        self,
+        custody::{self, CustodyRecord, EncryptedShare},
+        models::OperatorId,
+    },
+};
+
+const SHARE_AAD: &[u8] = b"arbiter/shamir-share/v1";
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("An ordinary committee is already being coordinated")]
+    AlreadyBootstrapping,
+    #[error("An unseal is already being coordinated")]
+    AlreadyUnsealing,
+    #[error("Bootstrap is not in progress")]
+    NotBootstrapping,
+    #[error("The operator already contributed")]
+    DuplicateContribution,
+    #[error("The ordinary committee cannot be empty")]
+    EmptyCommittee,
+    #[error("Two-operator committees are unsupported")]
+    UnsupportedCommittee,
+    #[error(
+        "The ordinary committee cannot exceed {} members",
+        shamir::MAX_COMMITTEE_SIZE
+    )]
+    CommitteeTooLarge,
+    #[error("Invalid passphrase")]
+    InvalidPassphrase,
+    #[error("Broken database")]
+    BrokenDatabase,
+    #[error("Shamir error: {0}")]
+    Shamir(String),
+    #[error("Database connection error: {0}")]
+    DatabaseConnection(#[from] db::PoolError),
+    #[error("Custody storage error: {0}")]
+    Custody(#[from] custody::Error),
+    #[error("Encryption error")]
+    Encryption,
+    #[error("The vault is already bootstrapped")]
+    AlreadyBootstrapped,
+    #[error("Vault error")]
+    Vault,
+}
+
+/// Passphrases gathered so far, in contribution order.
+///
+/// A `Vec` rather than a map because [`SafeCell`] values are neither cloneable
+/// nor hashable, and a committee holds at most
+/// [`shamir::MAX_COMMITTEE_SIZE`] of them.
+#[derive(Default)]
+struct Contributions(Vec<(OperatorId, SafeCell<Vec<u8>>)>);
+
+impl Contributions {
+    fn contains(&self, operator_id: OperatorId) -> bool {
+        self.0.iter().any(|(id, _)| *id == operator_id)
+    }
+
+    fn put(&mut self, operator_id: OperatorId, passphrase: SafeCell<Vec<u8>>) {
+        match self.0.iter_mut().find(|(id, _)| *id == operator_id) {
+            Some(slot) => slot.1 = passphrase,
+            None => self.0.push((operator_id, passphrase)),
+        }
+    }
+
+    const fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    fn operators(&self) -> Vec<OperatorId> {
+        self.0.iter().map(|(id, _)| *id).collect()
+    }
+}
+
+enum CoordinatorState {
+    Idle,
+    Bootstrapping {
+        /// The operator that declared the committee. Only they may re-declare
+        /// it, which is the way out of a ceremony the others never finish.
+        declarer: OperatorId,
+        declared_count: usize,
+        contributions: Contributions,
+        retryable: bool,
+    },
+    Unsealing {
+        threshold: usize,
+        contributions: Contributions,
+        retryable: bool,
+    },
+}
+
+#[derive(Actor)]
+pub struct VaultCoordinator {
+    db: db::DatabasePool,
+    vault: ActorRef<Vault>,
+    state: CoordinatorState,
+}
+
+impl VaultCoordinator {
+    pub const fn new(db: db::DatabasePool, vault: ActorRef<Vault>) -> Self {
+        Self {
+            db,
+            vault,
+            state: CoordinatorState::Idle,
+        }
+    }
+}
+
+/// Explain why a committee size was rejected.
+const fn committee_error(declared_count: usize) -> Error {
+    match declared_count {
+        0 => Error::EmptyCommittee,
+        2 => Error::UnsupportedCommittee,
+        _ => Error::CommitteeTooLarge,
+    }
+}
+
+fn encrypt_share(
+    passphrase: &mut SafeCell<Vec<u8>>,
+    share: &[u8],
+) -> Result<EncryptedShare, Error> {
+    let mut salt = [0u8; RECOMMENDED_SALT_LEN];
+    UnwrapErr(SysRng).fill_bytes(&mut salt);
+
+    let nonce = Nonce::default();
+    let ciphertext = derive_key(passphrase, &salt)
+        .encrypt(&nonce, SHARE_AAD, share)
+        .map_err(|_| Error::Encryption)?;
+
+    Ok(EncryptedShare {
+        ciphertext,
+        nonce: nonce.to_vec(),
+        salt: salt.to_vec(),
+    })
+}
+
+fn decrypt_share(
+    passphrase: &mut SafeCell<Vec<u8>>,
+    share: EncryptedShare,
+) -> Result<SafeCell<Vec<u8>>, Error> {
+    let nonce = Nonce::try_from(share.nonce.as_slice()).map_err(|()| Error::BrokenDatabase)?;
+
+    let mut buffer = SafeCell::new(share.ciphertext);
+    derive_key(passphrase, &share.salt)
+        .decrypt_in_place(&nonce, SHARE_AAD, &mut buffer)
+        .map_err(|_| Error::InvalidPassphrase)?;
+
+    Ok(buffer)
+}
+
+const fn bootstrap_error(error: &SendError<Bootstrap, vault::Error>) -> Error {
+    match error {
+        SendError::HandlerError(vault::Error::AlreadyBootstrapped) => Error::AlreadyBootstrapped,
+        _ => Error::Vault,
+    }
+}
+
+/// Build the custody record and hand it to the vault, which stores it in the
+/// same transaction as the root key.
+async fn finalize_bootstrap(
+    vault: &ActorRef<Vault>,
+    contributions: &mut Contributions,
+) -> Result<(), Error> {
+    let total = contributions.len();
+    let threshold = shamir::shamir_threshold(total).ok_or_else(|| committee_error(total))?;
+
+    let mut seal_key = KeyCell::new_secure_random();
+    let mut shares = shamir::split_key(threshold, total, &mut seal_key, UnwrapErr(SysRng))
+        .map_err(|error| Error::Shamir(error.to_string()))?;
+
+    if shares.len() < total {
+        return Err(Error::Shamir("missing share for operator".to_owned()));
+    }
+
+    let mut encrypted = Vec::with_capacity(total);
+    for ((operator_id, passphrase), share) in contributions.0.iter_mut().zip(shares.iter_mut()) {
+        let share = share.read_inline(|share| encrypt_share(passphrase, share))?;
+        encrypted.push((*operator_id, share));
+    }
+
+    vault
+        .ask(Bootstrap {
+            seal_key,
+            custody: Some(CustodyRecord {
+                threshold,
+                shares: encrypted,
+            }),
+        })
+        .await
+        .map_err(|error| bootstrap_error(&error))
+}
+
+/// Reconstruct the seal key from the contributed passphrases and unseal.
+async fn finalize_unseal(
+    db: &db::DatabasePool,
+    vault: &ActorRef<Vault>,
+    threshold: usize,
+    contributions: &mut Contributions,
+) -> Result<(), Error> {
+    let stored = {
+        let mut conn = db.get().await?;
+        custody::shares(&mut conn, &contributions.operators()).await?
+    };
+
+    let mut plaintext = Vec::with_capacity(stored.len());
+    for ((_, passphrase), share) in contributions.0.iter_mut().zip(stored) {
+        plaintext.push(decrypt_share(passphrase, share)?);
+    }
+
+    let seal_key = shamir::combine_shares(threshold, &mut plaintext)
+        .map_err(|error| Error::Shamir(error.to_string()))?;
+
+    vault
+        .ask(TryUnseal { seal_key })
+        .await
+        .map_err(|_| Error::Vault)
+}
+
+#[messages]
+impl VaultCoordinator {
+    /// Announce how many operators will contribute to the bootstrap.
+    ///
+    /// The declaring operator may re-declare to restart the ceremony; that is
+    /// the only way to release a committee whose members never all show up.
+    #[message]
+    pub fn start_bootstrap(
+        &mut self,
+        operator_id: OperatorId,
+        declared_count: usize,
+    ) -> Result<(), Error> {
+        if shamir::shamir_threshold(declared_count).is_none() {
+            return Err(committee_error(declared_count));
+        }
+
+        match &self.state {
+            CoordinatorState::Unsealing { .. } => return Err(Error::AlreadyUnsealing),
+            CoordinatorState::Bootstrapping { declarer, .. } if *declarer != operator_id => {
+                return Err(Error::AlreadyBootstrapping);
+            }
+            CoordinatorState::Bootstrapping { .. } | CoordinatorState::Idle => {}
+        }
+
+        self.state = CoordinatorState::Bootstrapping {
+            declarer: operator_id,
+            declared_count,
+            contributions: Contributions::default(),
+            retryable: false,
+        };
+        Ok(())
+    }
+
+    #[message]
+    pub async fn contribute_bootstrap(
+        &mut self,
+        operator_id: OperatorId,
+        passphrase: SafeCell<Vec<u8>>,
+    ) -> Result<bool, Error> {
+        let CoordinatorState::Bootstrapping {
+            declared_count,
+            contributions,
+            retryable,
+            ..
+        } = &mut self.state
+        else {
+            return Err(Error::NotBootstrapping);
+        };
+
+        if contributions.contains(operator_id) && !*retryable {
+            return Err(Error::DuplicateContribution);
+        }
+        contributions.put(operator_id, passphrase);
+        *retryable = false;
+
+        if contributions.len() < *declared_count {
+            return Ok(false);
+        }
+
+        let state = std::mem::replace(&mut self.state, CoordinatorState::Idle);
+        let CoordinatorState::Bootstrapping {
+            declarer,
+            declared_count,
+            mut contributions,
+            ..
+        } = state
+        else {
+            unreachable!("state was matched as Bootstrapping above")
+        };
+
+        match finalize_bootstrap(&self.vault, &mut contributions).await {
+            Ok(()) => Ok(true),
+            Err(error) => {
+                self.state = CoordinatorState::Bootstrapping {
+                    declarer,
+                    declared_count,
+                    contributions,
+                    retryable: true,
+                };
+                Err(error)
+            }
+        }
+    }
+
+    #[message]
+    pub async fn contribute_unseal(
+        &mut self,
+        operator_id: OperatorId,
+        passphrase: SafeCell<Vec<u8>>,
+    ) -> Result<bool, Error> {
+        if matches!(self.state, CoordinatorState::Idle) {
+            let threshold = {
+                let mut conn = self.db.get().await?;
+                custody::threshold(&mut conn).await?
+            };
+            self.state = CoordinatorState::Unsealing {
+                threshold,
+                contributions: Contributions::default(),
+                retryable: false,
+            };
+        }
+
+        let CoordinatorState::Unsealing {
+            threshold,
+            contributions,
+            retryable,
+        } = &mut self.state
+        else {
+            return Err(Error::AlreadyBootstrapping);
+        };
+
+        if contributions.contains(operator_id) && !*retryable {
+            return Err(Error::DuplicateContribution);
+        }
+        contributions.put(operator_id, passphrase);
+        *retryable = false;
+
+        if contributions.len() < *threshold {
+            return Ok(false);
+        }
+
+        let state = std::mem::replace(&mut self.state, CoordinatorState::Idle);
+        let CoordinatorState::Unsealing {
+            threshold,
+            mut contributions,
+            ..
+        } = state
+        else {
+            unreachable!("state was matched as Unsealing above")
+        };
+
+        match finalize_unseal(&self.db, &self.vault, threshold, &mut contributions).await {
+            Ok(()) => Ok(true),
+            Err(error) => {
+                self.state = CoordinatorState::Unsealing {
+                    threshold,
+                    contributions,
+                    retryable: true,
+                };
+                Err(error)
+            }
+        }
+    }
+}

server/crates/arbiter-server/src/crypto/encryption/v1.rs

@@ -61,12 +61,11 @@ mod tests {
     #[test]
     fn derive_seal_key_deterministic() {
         static PASSWORD: &[u8] = b"password";
-        let password = SafeCell::new(PASSWORD.to_vec());
+        let mut password = SafeCell::new(PASSWORD.to_vec());
-        let password2 = SafeCell::new(PASSWORD.to_vec());
         let salt = generate_salt();
 
-        let mut key1 = derive_key(password, &salt);
+        let mut key1 = derive_key(&mut password, &salt);
-        let mut key2 = derive_key(password2, &salt);
+        let mut key2 = derive_key(&mut password, &salt);
 
         let key1_reader = key1.0.read();
         let key2_reader = key2.0.read();
@@ -77,10 +76,10 @@ mod tests {
     #[test]
     fn successful_derive() {
         static PASSWORD: &[u8] = b"password";
-        let password = SafeCell::new(PASSWORD.to_vec());
+        let mut password = SafeCell::new(PASSWORD.to_vec());
         let salt = generate_salt();
 
-        let mut key = derive_key(password, &salt);
+        let mut key = derive_key(&mut password, &salt);
         let key_reader = key.0.read();
 
         assert_ne!(key_reader.as_slice(), &[0u8; 32][..]);

server/crates/arbiter-server/src/crypto/integrity/v1.rs

@@ -192,7 +192,9 @@ pub async fn verify_entity<E: Integrable>(
         Ok(false) => Err(Error::MacMismatch {
             entity_kind: E::KIND,
         }),
-        Err(SendError::HandlerError(vault::Error::Sealed)) => Ok(AttestationStatus::Unavailable),
+        Err(SendError::HandlerError(
+            vault::Error::Sealed | vault::Error::KeyVersionMismatch { .. },
+        )) => Ok(AttestationStatus::Unavailable),
         Err(_) => Err(Error::VaultSend),
     }
 }
@@ -213,9 +215,9 @@ mod tests {
             GlobalActors,
             vault::{Bootstrap, Vault},
         },
+        crypto::KeyCell,
         db::{self, schema},
     };
-    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 
     use super::{Error, Integrable, sign_entity, verify_entity};
     #[derive(Clone, arbiter_macros::Hashable)]
@@ -235,7 +237,8 @@ mod tests {
         );
         actor
             .ask(Bootstrap {
-                seal_key_raw: SafeCell::new(b"integrity-test-seal-key".to_vec()),
+                seal_key: KeyCell::from([0u8; 32]),
+                custody: None,
             })
             .await
             .unwrap();
@@ -331,4 +334,47 @@ mod tests {
             .unwrap_err();
         assert!(matches!(err, Error::MacMismatch { .. }));
     }
+
+    #[tokio::test]
+    async fn key_version_mismatch_returns_unavailable_not_mac_mismatch() {
+        use crate::db::schema::integrity_envelope;
+        use super::AttestationStatus;
+
+        const ENTITY_ID: &[u8] = b"entity-id-rotation-test";
+
+        let db = db::create_test_pool().await;
+        let vault = bootstrapped_vault(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &vault, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+
+        // Simulate key rotation: update the stored key_version to a stale value.
+        // After real rotation the vault's root_key_history_id would advance, but
+        // here we achieve the same mismatch by back-dating the envelope's key_version.
+        diesel::update(integrity_envelope::table)
+            .filter(integrity_envelope::entity_kind.eq("dummy_entity"))
+            .filter(integrity_envelope::entity_id.eq(ENTITY_ID))
+            .set(integrity_envelope::key_version.eq(0))
+            .execute(&mut conn)
+            .await
+            .unwrap();
+
+        // Must NOT error — version mismatch is Unavailable, not tampered.
+        let status = verify_entity(&mut conn, &vault, &entity, ENTITY_ID)
+            .await
+            .expect("key version mismatch must not be treated as an error");
+
+        assert_eq!(
+            status,
+            AttestationStatus::Unavailable,
+            "stale key_version must yield Unavailable, not MacMismatch"
+        );
+    }
 }

server/crates/arbiter-server/src/crypto/mod.rs

@@ -1,5 +1,5 @@
 use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
-use encryption::v1::{Nonce, Salt};
+use encryption::v1::Nonce;
 
 use argon2::{Algorithm, Argon2};
 use chacha20poly1305::{
@@ -13,6 +13,7 @@ use rand::{
 
 pub mod encryption;
 pub mod integrity;
+pub mod shamir;
 
 pub struct KeyCell(pub SafeCell<Key>);
 impl From<SafeCell<Key>> for KeyCell {
@@ -20,6 +21,16 @@ impl From<SafeCell<Key>> for KeyCell {
         Self(value)
     }
 }
+
+impl From<[u8; 32]> for KeyCell {
+    fn from(bytes: [u8; 32]) -> Self {
+        let cell = SafeCell::new_inline(|key: &mut Key| {
+            key.copy_from_slice(&bytes);
+        });
+        Self(cell)
+    }
+}
+
 impl TryFrom<SafeCell<Vec<u8>>> for KeyCell {
     type Error = ();
 
@@ -58,6 +69,7 @@ impl KeyCell {
         let buffer = buffer.as_mut();
         cipher.encrypt_in_place(nonce, associated_data, buffer)
     }
+
     pub fn decrypt_in_place(
         &mut self,
         nonce: &Nonce,
@@ -93,8 +105,11 @@ impl KeyCell {
     }
 }
 
-/// Derive a fixed-length key from the password using Argon2id, which is designed for password hashing and key derivation.
+/// Derive a fixed-length key from a passphrase using Argon2id.
-pub fn derive_key(mut password: SafeCell<Vec<u8>>, salt: &Salt) -> KeyCell {
+///
+/// The passphrase is borrowed so that callers can keep it in protected memory
+/// and reuse it across retries instead of handing over a copy.
+pub fn derive_key(password: &mut SafeCell<Vec<u8>>, salt: &[u8]) -> KeyCell {
     let params = {
         #[cfg(debug_assertions)]
         {
@@ -132,11 +147,11 @@ mod tests {
     #[test]
     fn encrypt_decrypt() {
         static PASSWORD: &[u8] = b"password";
-        let password = SafeCell::new(PASSWORD.to_vec());
+        let mut password = SafeCell::new(PASSWORD.to_vec());
         let salt = generate_salt();
 
-        let mut key = derive_key(password, &salt);
+        let mut key = derive_key(&mut password, &salt);
-        let nonce = Nonce(*b"unique nonce 123 1231233"); // 24 bytes for XChaCha20Poly1305
+        let nonce = Nonce(*b"unique nonce 123 1231233");
         let associated_data = b"associated data";
         let mut buffer = b"secret data".to_vec();
 

server/crates/arbiter-server/src/crypto/shamir.rs

@@ -0,0 +1,221 @@
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+use rand_core::CryptoRng;
+use vsss_rs::Gf256;
+
+use crate::crypto::KeyCell;
+
+/// GF(256) addresses shares by a non-zero byte, so no committee can exceed 255.
+pub const MAX_COMMITTEE_SIZE: usize = 255;
+
+/// Errors returned by Shamir split/combine operations.
+#[derive(Debug, thiserror::Error)]
+pub enum ShamirError {
+    #[error("failed to split key: {0}")]
+    Split(String),
+    #[error("failed to combine shares: {0}")]
+    Combine(String),
+}
+
+/// Return the required threshold for a Shamir share pool of `committee_size`.
+///
+/// A pool of two is rejected: a majority of two is two, which gives each holder
+/// a veto over every unseal without giving either one recovery. That rejects no
+/// supported committee, because a two-operator vault must carry at least one
+/// recovery share and so never splits into a pool of two -- see
+/// `docs/ARCHITECTURE.md` 3.9.
+#[expect(
+    clippy::integer_division,
+    reason = "majority thresholds use integer arithmetic"
+)]
+#[must_use]
+pub const fn shamir_threshold(committee_size: usize) -> Option<usize> {
+    match committee_size {
+        0 | 2 => None,
+        size if size > MAX_COMMITTEE_SIZE => None,
+        1 => Some(1),
+        size => Some(size / 2 + 1),
+    }
+}
+
+/// Split a seal key into `total` shares, `threshold` of which reconstruct it.
+pub fn split_key(
+    threshold: usize,
+    total: usize,
+    key: &mut KeyCell,
+    rng: impl CryptoRng,
+) -> Result<Vec<SafeCell<Vec<u8>>>, ShamirError> {
+    if total == 0 || threshold == 0 || threshold > total || total == 2 || total > MAX_COMMITTEE_SIZE
+    {
+        return Err(ShamirError::Split(
+            "unsupported committee parameters".to_owned(),
+        ));
+    }
+
+    // Nothing to interpolate when one share suffices.
+    if threshold == 1 {
+        return Ok(key.0.read_inline(|key| {
+            std::iter::repeat_with(|| SafeCell::new(key.as_slice().to_vec()))
+                .take(total)
+                .collect()
+        }));
+    }
+
+    key.0.read_inline(|key| {
+        let key: &[u8; 32] = key
+            .as_slice()
+            .try_into()
+            .map_err(|_| ShamirError::Split("unexpected seal key length".to_owned()))?;
+
+        Gf256::split_array(threshold, total, key, rng)
+            .map(|shares| shares.into_iter().map(SafeCell::new).collect())
+            .map_err(|error| ShamirError::Split(format!("{error:?}")))
+    })
+}
+
+/// Combine shares back into the seal key.
+///
+/// `threshold` comes from storage rather than from the shapes of the shares:
+/// a one-of-one committee stores the key verbatim, and telling that apart by
+/// share length alone would misread any Shamir share that happened to be key
+/// sized.
+pub fn combine_shares(
+    threshold: usize,
+    shares: &mut [SafeCell<Vec<u8>>],
+) -> Result<KeyCell, ShamirError> {
+    if threshold == 0 {
+        return Err(ShamirError::Combine("threshold is zero".to_owned()));
+    }
+    if shares.len() < threshold {
+        return Err(ShamirError::Combine(
+            "not enough shares supplied".to_owned(),
+        ));
+    }
+
+    // Mirror of the one-of-one case in [`split_key`]: the share is the key.
+    if threshold == 1 {
+        let share = shares
+            .first_mut()
+            .ok_or_else(|| ShamirError::Combine("no shares supplied".to_owned()))?;
+        return reconstructed_key(share.read_inline(|share| SafeCell::new(share.clone())));
+    }
+
+    let mut gathered = SafeCell::new(Vec::with_capacity(shares.len()));
+    for share in shares.iter_mut() {
+        share.read_inline(|share| {
+            gathered.write_inline(|gathered| gathered.push(share.clone()));
+        });
+    }
+
+    let combined = gathered.read_inline(|gathered| {
+        Gf256::combine_array(gathered.as_slice())
+            .map(SafeCell::new)
+            .map_err(|error| ShamirError::Combine(format!("{error:?}")))
+    })?;
+
+    reconstructed_key(combined)
+}
+
+fn reconstructed_key(bytes: SafeCell<Vec<u8>>) -> Result<KeyCell, ShamirError> {
+    KeyCell::try_from(bytes)
+        .map_err(|()| ShamirError::Combine("unexpected reconstructed key length".to_owned()))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{MAX_COMMITTEE_SIZE, combine_shares, shamir_threshold, split_key};
+    use crate::crypto::KeyCell;
+    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+    use rand::rngs::SysRng;
+    use rand_core::UnwrapErr;
+    use rstest::rstest;
+
+    fn key_bytes(mut key: KeyCell) -> [u8; 32] {
+        key.0.read_inline(|key| {
+            let mut bytes = [0u8; 32];
+            bytes.copy_from_slice(key.as_slice());
+            bytes
+        })
+    }
+
+    fn select(shares: &mut [SafeCell<Vec<u8>>], indexes: &[usize]) -> Vec<SafeCell<Vec<u8>>> {
+        indexes
+            .iter()
+            .filter_map(|index| {
+                shares
+                    .get_mut(*index)
+                    .map(|share| share.read_inline(|share| SafeCell::new(share.clone())))
+            })
+            .collect()
+    }
+
+    #[rstest]
+    #[case(&[0, 1])]
+    #[case(&[0, 2])]
+    #[case(&[1, 2])]
+    fn threshold_shares_reconstruct_fixed_key(#[case] indexes: &[usize]) {
+        let expected = [9_u8; 32];
+        let mut key = KeyCell::from(expected);
+        let rng = UnwrapErr(SysRng);
+        let mut shares = split_key(2, 3, &mut key, rng).expect("split should succeed");
+        let mut selected = select(&mut shares, indexes);
+        let combined = combine_shares(2, &mut selected).expect("combine should succeed");
+        assert_eq!(key_bytes(combined), expected);
+    }
+
+    #[test]
+    fn one_of_one_round_trips_a_fixed_size_key() {
+        let expected = [7_u8; 32];
+        let mut key = KeyCell::from(expected);
+        let rng = UnwrapErr(SysRng);
+        let mut shares = split_key(1, 1, &mut key, rng).expect("split should succeed");
+        let combined = combine_shares(1, &mut shares).expect("combine should succeed");
+        assert_eq!(key_bytes(combined), expected);
+    }
+
+    #[test]
+    fn fewer_shares_than_threshold_is_rejected() {
+        let mut key = KeyCell::from([3_u8; 32]);
+        let rng = UnwrapErr(SysRng);
+        let mut shares = split_key(3, 5, &mut key, rng).expect("split should succeed");
+        let mut selected = select(&mut shares, &[0, 1]);
+        assert!(
+            combine_shares(3, &mut selected).is_err(),
+            "two of three shares must not reconstruct the key"
+        );
+    }
+
+    #[rstest]
+    #[case(0, None)]
+    #[case(1, Some(1))]
+    #[case(2, None)]
+    #[case(3, Some(2))]
+    #[case(4, Some(3))]
+    #[case(MAX_COMMITTEE_SIZE, Some(128))]
+    #[case(MAX_COMMITTEE_SIZE + 1, None)]
+    fn committee_threshold_is_a_majority(
+        #[case] committee_size: usize,
+        #[case] expected: Option<usize>,
+    ) {
+        assert_eq!(shamir_threshold(committee_size), expected);
+    }
+
+    #[test]
+    fn oversized_committee_is_rejected_by_split() {
+        let mut key = KeyCell::from([1_u8; 32]);
+        let rng = UnwrapErr(SysRng);
+        assert!(
+            split_key(129, MAX_COMMITTEE_SIZE + 1, &mut key, rng).is_err(),
+            "committees above the GF(256) share limit must be rejected"
+        );
+    }
+
+    #[test]
+    fn two_operator_committee_is_explicitly_unsupported() {
+        let mut key = KeyCell::from([7_u8; 32]);
+        let rng = UnwrapErr(SysRng);
+        assert!(
+            split_key(2, 2, &mut key, rng).is_err(),
+            "two-operator committees must be rejected"
+        );
+    }
+}

server/crates/arbiter-server/src/db/custody.rs

@@ -0,0 +1,137 @@
+//! Storage for Shamir custody material: the reconstruction threshold and the
+//! per-operator encrypted shares of the vault seal key.
+//!
+//! The queries live here so that the actors above hold no Diesel code of their
+//! own. Every one of them borrows the caller's connection instead of taking one
+//! from the pool, which is what lets the vault write custody material inside
+//! the same transaction that stores the root key.
+
+use std::collections::HashMap;
+
+use diesel::{ExpressionMethods as _, QueryDsl};
+use diesel_async::RunQueryDsl;
+
+use crate::db::{
+    self,
+    models::{OperatorId, SqliteTimestamp},
+    schema,
+};
+
+/// One Shamir share, encrypted under a key derived from its operator's passphrase.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct EncryptedShare {
+    pub ciphertext: Vec<u8>,
+    pub nonce: Vec<u8>,
+    pub salt: Vec<u8>,
+}
+
+/// Everything a bootstrap persists about custody, written as a single unit.
+#[derive(Debug)]
+pub struct CustodyRecord {
+    pub threshold: usize,
+    pub shares: Vec<(OperatorId, EncryptedShare)>,
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("Database query error: {0}")]
+    Query(#[from] diesel::result::Error),
+    #[error("Stored committee threshold is missing or out of range")]
+    BrokenThreshold,
+    #[error("Custody settings row is missing")]
+    MissingSettings,
+    #[error("No share stored for operator {0:?}")]
+    MissingShare(OperatorId),
+}
+
+/// Persist threshold and shares on the caller's connection, joining any
+/// transaction the caller has already opened.
+pub async fn write_record(
+    conn: &mut db::DatabaseConnection,
+    record: &CustodyRecord,
+) -> Result<(), Error> {
+    let threshold = i32::try_from(record.threshold).map_err(|_| Error::BrokenThreshold)?;
+
+    // SQLite has no batch form for REPLACE INTO in diesel, so the rows go
+    // in one at a time. The caller's transaction still makes them atomic.
+    let now = SqliteTimestamp::now();
+    for (operator_id, share) in &record.shares {
+        diesel::replace_into(schema::operator::table)
+            .values((
+                schema::operator::id.eq(Some(*operator_id)),
+                schema::operator::share.eq(&share.ciphertext),
+                schema::operator::share_nonce.eq(&share.nonce),
+                schema::operator::share_salt.eq(&share.salt),
+                schema::operator::created_at.eq(now.clone()),
+                schema::operator::updated_at.eq(now.clone()),
+            ))
+            .execute(&mut *conn)
+            .await?;
+    }
+
+    let updated = diesel::update(schema::arbiter_settings::table)
+        .set(schema::arbiter_settings::shamir_threshold.eq(Some(threshold)))
+        .execute(&mut *conn)
+        .await?;
+    if updated != 1 {
+        return Err(Error::MissingSettings);
+    }
+
+    Ok(())
+}
+
+/// Number of shares required to reconstruct the seal key.
+pub async fn threshold(conn: &mut db::DatabaseConnection) -> Result<usize, Error> {
+    let stored: Option<i32> = schema::arbiter_settings::table
+        .select(schema::arbiter_settings::shamir_threshold)
+        .first(conn)
+        .await?;
+
+    stored
+        .and_then(|value| usize::try_from(value).ok())
+        .filter(|threshold| *threshold > 0)
+        .ok_or(Error::BrokenThreshold)
+}
+
+/// Load the shares of `operators` in one query, in the order requested.
+pub async fn shares(
+    conn: &mut db::DatabaseConnection,
+    operators: &[OperatorId],
+) -> Result<Vec<EncryptedShare>, Error> {
+    /// (id, then the three columns that make up [`EncryptedShare`])
+    type ShareRow = (Option<OperatorId>, Vec<u8>, Vec<u8>, Vec<u8>);
+
+    let wanted: Vec<Option<OperatorId>> = operators.iter().copied().map(Some).collect();
+
+    let rows: Vec<ShareRow> = schema::operator::table
+        .filter(schema::operator::id.eq_any(wanted))
+        .select((
+            schema::operator::id,
+            schema::operator::share,
+            schema::operator::share_nonce,
+            schema::operator::share_salt,
+        ))
+        .load(conn)
+        .await?;
+
+    let mut found: HashMap<OperatorId, EncryptedShare> = rows
+        .into_iter()
+        .filter_map(|(id, ciphertext, nonce, salt)| {
+            id.map(|id| {
+                (
+                    id,
+                    EncryptedShare {
+                        ciphertext,
+                        nonce,
+                        salt,
+                    },
+                )
+            })
+        })
+        .collect();
+
+    operators
+        .iter()
+        .map(|id| found.remove(id).ok_or(Error::MissingShare(*id)))
+        .collect()
+}

server/crates/arbiter-server/src/db/mod.rs

@@ -8,6 +8,7 @@ use diesel_migrations::{EmbeddedMigrations, MigrationHarness, embed_migrations};
 use thiserror::Error;
 use tracing::info;
 
+pub mod custody;
 pub mod models;
 pub mod schema;
 
@@ -154,3 +155,39 @@ pub async fn create_test_pool() -> DatabasePool {
         .await
         .expect("Failed to create test database pool")
 }
+
+#[cfg(test)]
+mod tests {
+    use diesel::{ExpressionMethods as _, result::DatabaseErrorKind};
+    use diesel_async::RunQueryDsl as _;
+
+    use super::*;
+
+    #[tokio::test]
+    async fn operator_share_salt_must_be_supplied_by_application() {
+        let pool = create_test_pool().await;
+        let mut conn = pool.get().await.expect("pool connection");
+
+        let operator_id = diesel::insert_into(schema::operator_identity::table)
+            .values(schema::operator_identity::public_key.eq(vec![1]))
+            .returning(schema::operator_identity::id)
+            .get_result::<i32>(&mut conn)
+            .await
+            .expect("insert operator identity");
+
+        let error = diesel::insert_into(schema::operator::table)
+            .values((
+                schema::operator::id.eq(operator_id),
+                schema::operator::share.eq(vec![2]),
+                schema::operator::share_nonce.eq(vec![3]),
+            ))
+            .execute(&mut conn)
+            .await
+            .expect_err("operator insert without an application-generated salt must fail");
+
+        assert!(matches!(
+            error,
+            diesel::result::Error::DatabaseError(DatabaseErrorKind::NotNullViolation, _)
+        ));
+    }
+}

server/crates/arbiter-server/src/db/models.rs

@@ -110,6 +110,18 @@ pub mod types {
                     ToSql::<Integer, Sqlite>::to_sql(&self.0, out)
                 }
             }
+
+            impl arbiter_crypto::hashing::Hashable for $name {
+                fn hash<H: arbiter_crypto::hashing::Digest>(&self, hasher: &mut H) {
+                    arbiter_crypto::hashing::Hashable::hash(&self.0, hasher);
+                }
+            }
+
+            impl crate::crypto::integrity::v1::IntoId for $name {
+                fn into_id(self) -> Vec<u8> {
+                    crate::crypto::integrity::v1::IntoId::into_id(self.0)
+                }
+            }
         };
     }
 
@@ -203,6 +215,7 @@ pub struct ArbiterSettings {
     pub id: i32,
     pub root_key_id: Option<i32>, // references root_key_history.id
     pub tls_id: Option<i32>,      // references tls_history.id
+    pub shamir_threshold: Option<i32>,
 }
 
 #[derive(Models, Queryable, Debug, Insertable, Selectable)]
@@ -285,6 +298,7 @@ pub struct Operator {
     pub id: OperatorId,
     pub share: Vec<u8>,
     pub share_nonce: Vec<u8>,
+    pub share_salt: Vec<u8>,
     pub created_at: SqliteTimestamp,
     pub updated_at: SqliteTimestamp,
 }

server/crates/arbiter-server/src/db/schema.rs

@@ -17,6 +17,7 @@ diesel::table! {
         id -> Integer,
         root_key_id -> Nullable<Integer>,
         tls_id -> Nullable<Integer>,
+        shamir_threshold -> Nullable<Integer>,
     }
 }
 
@@ -157,6 +158,7 @@ diesel::table! {
         id -> Nullable<Integer>,
         share -> Binary,
         share_nonce -> Binary,
+        share_salt -> Binary,
         created_at -> Integer,
         updated_at -> Integer,
     }

server/crates/arbiter-server/src/evm/mod.rs

@@ -1,28 +1,34 @@
+use diesel_async::{AsyncConnection, RunQueryDsl};
+use kameo::actor::ActorRef;
+
 use crate::{
     actors::vault::Vault,
     crypto::integrity,
     db::{
         self, DatabaseError,
         models::{
-            EvmBasicGrant, EvmWalletAccess, NewEvmBasicGrant, NewEvmTransactionLog, SqliteTimestamp,
+            EvmBasicGrant, EvmEtherTransferGrant, EvmEtherTransferGrantTarget,
+            EvmEtherTransferLimit, EvmTokenTransferGrant, EvmTokenTransferVolumeLimit,
+            EvmWalletAccess, NewEvmBasicGrant, NewEvmTransactionLog, SqliteTimestamp,
         },
         schema::{self, evm_transaction_log},
     },
     evm::policies::{
         CombinedSettings, DatabaseID, EvalContext, EvalViolation, Grant, Policy,
-        SharedGrantSettings, SpecificGrant, SpecificMeaning, ether_transfer::EtherTransfer,
+        SharedGrantSettings, SpecificGrant, SpecificMeaning, VolumeRateLimit,
-        token_transfers::TokenTransfer,
+        ether_transfer::EtherTransfer, token_transfers::TokenTransfer,
     },
 };
 
 use alloy::{
     consensus::TxEip1559,
-    primitives::{TxKind, U256},
+    primitives::{Address, TxKind, U256},
 };
 use chrono::Utc;
-use diesel::{ExpressionMethods as _, QueryDsl as _, QueryResult, insert_into, sqlite::Sqlite};
+use diesel::{
-use diesel_async::{AsyncConnection, RunQueryDsl};
+    ExpressionMethods as _, OptionalExtension, QueryDsl as _, QueryResult, SelectableHelper,
-use kameo::actor::ActorRef;
+    insert_into, sqlite::Sqlite, update,
+};
 
 pub mod abi;
 pub mod safe_signer;
@@ -272,6 +278,151 @@ impl Engine {
         Ok(id)
     }
 
+    pub async fn revoke_grant(
+        &self,
+        basic_grant_id: i32,
+    ) -> Result<(), DatabaseError> {
+        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
+        let vault = self.vault.clone();
+
+        conn.transaction(async move |conn| {
+            use crate::db::schema::{
+                evm_basic_grant, evm_ether_transfer_grant, evm_ether_transfer_grant_target,
+                evm_ether_transfer_limit, evm_token_transfer_grant,
+                evm_token_transfer_volume_limit,
+            };
+
+            update(evm_basic_grant::table)
+                .filter(evm_basic_grant::id.eq(basic_grant_id))
+                .set(evm_basic_grant::revoked_at.eq(SqliteTimestamp(Utc::now())))
+                .execute(&mut *conn)
+                .await?;
+
+            let basic_grant: EvmBasicGrant = evm_basic_grant::table
+                .filter(evm_basic_grant::id.eq(basic_grant_id))
+                .select(EvmBasicGrant::as_select())
+                .first(&mut *conn)
+                .await?;
+
+            let shared = SharedGrantSettings::try_from_model(basic_grant)?;
+
+            if let Some(ether_grant) = evm_ether_transfer_grant::table
+                .filter(evm_ether_transfer_grant::basic_grant_id.eq(basic_grant_id))
+                .select(EvmEtherTransferGrant::as_select())
+                .first(&mut *conn)
+                .await
+                .optional()?
+            {
+                let target_rows: Vec<EvmEtherTransferGrantTarget> =
+                    evm_ether_transfer_grant_target::table
+                        .filter(evm_ether_transfer_grant_target::grant_id.eq(ether_grant.id))
+                        .select(EvmEtherTransferGrantTarget::as_select())
+                        .load(&mut *conn)
+                        .await?;
+                let targets: Vec<Address> = target_rows
+                    .into_iter()
+                    .filter_map(|target| {
+                        let arr: [u8; 20] = target.address.try_into().ok()?;
+                        Some(Address::from(arr))
+                    })
+                    .collect();
+
+                let limit: EvmEtherTransferLimit = evm_ether_transfer_limit::table
+                    .filter(evm_ether_transfer_limit::id.eq(ether_grant.limit_id))
+                    .select(EvmEtherTransferLimit::as_select())
+                    .first(&mut *conn)
+                    .await?;
+
+                let settings = CombinedSettings {
+                    shared: shared.clone(),
+                    specific: policies::ether_transfer::Settings {
+                        target: targets,
+                        limit: VolumeRateLimit {
+                            max_volume: utils::try_bytes_to_u256(&limit.max_volume).map_err(
+                                |err| {
+                                    diesel::result::Error::DeserializationError(Box::new(err))
+                                },
+                            )?,
+                            window: chrono::Duration::seconds(limit.window_secs.into()),
+                        },
+                    },
+                };
+
+                integrity::sign_entity(&mut *conn, &vault, &settings, basic_grant_id)
+                    .await
+                    .map_err(|_| diesel::result::Error::RollbackTransaction)?;
+
+                return QueryResult::Ok(());
+            }
+
+            if let Some(token_grant) = evm_token_transfer_grant::table
+                .filter(evm_token_transfer_grant::basic_grant_id.eq(basic_grant_id))
+                .select(EvmTokenTransferGrant::as_select())
+                .first(&mut *conn)
+                .await
+                .optional()?
+            {
+                let volume_limit_rows: Vec<EvmTokenTransferVolumeLimit> =
+                    evm_token_transfer_volume_limit::table
+                        .filter(evm_token_transfer_volume_limit::grant_id.eq(token_grant.id))
+                        .select(EvmTokenTransferVolumeLimit::as_select())
+                        .load(&mut *conn)
+                        .await?;
+                let volume_limits: Vec<VolumeRateLimit> = volume_limit_rows
+                    .into_iter()
+                    .map(|row| {
+                        Ok(VolumeRateLimit {
+                            max_volume: utils::try_bytes_to_u256(&row.max_volume).map_err(
+                                |err| {
+                                    diesel::result::Error::DeserializationError(Box::new(err))
+                                },
+                            )?,
+                            window: chrono::Duration::seconds(row.window_secs.into()),
+                        })
+                    })
+                    .collect::<QueryResult<Vec<_>>>()?;
+
+                let target: Option<Address> = match token_grant.receiver {
+                    None => None,
+                    Some(bytes) => {
+                        let arr: [u8; 20] = bytes.try_into().map_err(|_| {
+                            diesel::result::Error::DeserializationError(
+                                "Invalid receiver address length".into(),
+                            )
+                        })?;
+                        Some(Address::from(arr))
+                    }
+                };
+
+                let token_contract: [u8; 20] =
+                    token_grant.token_contract.clone().try_into().map_err(|_| {
+                        diesel::result::Error::DeserializationError(
+                            "Invalid token contract address length".into(),
+                        )
+                    })?;
+
+                let settings = CombinedSettings {
+                    shared,
+                    specific: policies::token_transfers::Settings {
+                        token_contract: Address::from(token_contract),
+                        target,
+                        volume_limits,
+                    },
+                };
+
+                integrity::sign_entity(&mut *conn, &vault, &settings, basic_grant_id)
+                    .await
+                    .map_err(|_| diesel::result::Error::RollbackTransaction)?;
+
+                return QueryResult::Ok(());
+            }
+
+            Err(diesel::result::Error::NotFound)
+        })
+        .await
+        .map_err(DatabaseError::from)
+    }
+
     async fn list_one_kind<Kind: Policy, Y>(
         &self,
         conn: &mut impl AsyncConnection<Backend = Sqlite>,
@@ -354,8 +505,12 @@ mod tests {
     use chrono::{Duration, Utc};
     use diesel::{SelectableHelper, insert_into};
     use diesel_async::RunQueryDsl;
+    use kameo::{actor::ActorRef, prelude::Spawn};
     use rstest::rstest;
 
+    use crate::actors::{GlobalActors, vault::{Bootstrap, Vault}};
+    use crate::crypto::KeyCell;
+    use crate::crypto::integrity;
     use crate::db::{
         self, DatabaseConnection,
         models::{
@@ -364,8 +519,10 @@ mod tests {
         },
         schema::{evm_basic_grant, evm_transaction_log},
     };
+    use crate::evm::policies::ether_transfer::EtherTransfer;
     use crate::evm::policies::{
-        EvalContext, EvalViolation, SharedGrantSettings, TransactionRateLimit,
+        CombinedSettings, EvalContext, EvalViolation, Policy, SharedGrantSettings,
+        TransactionRateLimit, VolumeRateLimit,
     };
 
     use super::check_shared_constraints;
@@ -397,6 +554,7 @@ mod tests {
             chain: CHAIN_ID,
             valid_from: None,
             valid_until: None,
+            revoked_at: None,
             max_gas_fee_per_gas: None,
             max_priority_fee_per_gas: None,
             rate_limit: None,
@@ -605,4 +763,116 @@ mod tests {
             assert!(violations.is_empty());
         }
     }
+
+    async fn bootstrapped_vault(db: &db::DatabasePool) -> ActorRef<Vault> {
+        let actor = Vault::spawn(
+            Vault::new(db.clone(), GlobalActors::spawn_message_bus())
+                .await
+                .unwrap(),
+        );
+        actor
+            .ask(Bootstrap {
+                seal_key: KeyCell::from([0u8; 32]),
+                custody: None,
+            })
+            .await
+            .unwrap();
+        actor
+    }
+
+    #[tokio::test]
+    async fn revoke_grant_preserves_revoked_integrity() {
+        use crate::db::schema::evm_basic_grant;
+        use diesel::ExpressionMethods as _;
+
+        let db = db::create_test_pool().await;
+        let vault = bootstrapped_vault(&db).await;
+        let engine = super::Engine::new(db.clone(), vault.clone());
+
+        let full_grant = CombinedSettings {
+            shared: SharedGrantSettings {
+                wallet_access_id: WALLET_ACCESS_ID,
+                chain: CHAIN_ID,
+                valid_from: None,
+                valid_until: None,
+                revoked_at: None,
+                max_gas_fee_per_gas: None,
+                max_priority_fee_per_gas: None,
+                rate_limit: None,
+            },
+            specific: super::policies::ether_transfer::Settings {
+                target: vec![RECIPIENT],
+                limit: VolumeRateLimit {
+                    max_volume: U256::from(100u64),
+                    window: Duration::hours(1),
+                },
+            },
+        };
+
+        let grant_id = engine
+            .create_grant::<EtherTransfer>(full_grant)
+            .await
+            .unwrap();
+
+        engine.revoke_grant(grant_id).await.unwrap();
+
+        let mut conn = db.get().await.unwrap();
+        diesel::update(evm_basic_grant::table)
+            .filter(evm_basic_grant::id.eq(grant_id))
+            .set(evm_basic_grant::revoked_at.eq::<Option<SqliteTimestamp>>(None))
+            .execute(&mut conn)
+            .await
+            .unwrap();
+
+        let wallet_access = EvmWalletAccess {
+            id: WALLET_ACCESS_ID,
+            wallet_id: EvmWalletId::from_raw(10),
+            client_id: 20,
+            created_at: SqliteTimestamp(Utc::now()),
+        };
+        let context = EvalContext {
+            target: wallet_access,
+            chain: CHAIN_ID,
+            to: RECIPIENT,
+            value: U256::ONE,
+            calldata: Bytes::new(),
+            max_fee_per_gas: 1,
+            max_priority_fee_per_gas: 1,
+        };
+
+        let grant = EtherTransfer::try_find_grant(
+            &context, &mut conn,
+        )
+        .await
+        .unwrap()
+        .unwrap();
+
+        let result =
+            integrity::verify_entity(&mut conn, &vault, &grant.settings, grant.id).await;
+
+        assert!(matches!(
+            result,
+            Err(integrity::Error::MacMismatch { .. })
+        ));
+    }
+
+    #[test]
+    fn shared_settings_hash_changes_when_revoked_at_changes() {
+        use arbiter_crypto::hashing::Hashable;
+        use sha2::Digest;
+
+        let active = shared_settings();
+        let revoked = SharedGrantSettings {
+            revoked_at: Some(Utc::now()),
+            ..shared_settings()
+        };
+
+        let mut active_hash = sha2::Sha256::new();
+        active.hash(&mut active_hash);
+
+        let mut revoked_hash = sha2::Sha256::new();
+        revoked.hash(&mut revoked_hash);
+
+        assert_ne!(active_hash.finalize(), revoked_hash.finalize());
+    }
 }

server/crates/arbiter-server/src/evm/policies.rs

@@ -144,6 +144,7 @@ pub struct SharedGrantSettings {
 
     pub valid_from: Option<DateTime<Utc>>,
     pub valid_until: Option<DateTime<Utc>>,
+    pub revoked_at: Option<DateTime<Utc>>,
 
     pub max_gas_fee_per_gas: Option<U256>,
     pub max_priority_fee_per_gas: Option<U256>,
@@ -158,6 +159,7 @@ impl SharedGrantSettings {
             chain: model.chain_id.into(),
             valid_from: model.valid_from.map(Into::into),
             valid_until: model.valid_until.map(Into::into),
+            revoked_at: model.revoked_at.map(Into::into),
             max_gas_fee_per_gas: model
                 .max_gas_fee_per_gas
                 .map(|b| utils::try_bytes_to_u256(&b))

server/crates/arbiter-server/src/evm/policies/ether_transfer/tests.rs

@@ -80,6 +80,7 @@ fn shared() -> SharedGrantSettings {
         chain: CHAIN_ID,
         valid_from: None,
         valid_until: None,
+        revoked_at: None,
         max_gas_fee_per_gas: None,
         max_priority_fee_per_gas: None,
         rate_limit: None,

server/crates/arbiter-server/src/evm/policies/token_transfers/tests.rs

@@ -98,6 +98,7 @@ fn shared() -> SharedGrantSettings {
         chain: CHAIN_ID,
         valid_from: None,
         valid_until: None,
+        revoked_at: None,
         max_gas_fee_per_gas: None,
         max_priority_fee_per_gas: None,
         rate_limit: None,

server/crates/arbiter-server/src/grpc/client/auth.rs

@@ -200,7 +200,7 @@ impl Convert for auth::Outbound {
                         .timestamp
                         .timestamp_nanos_opt()
                         .expect("timestamp within range")
-                        as u64,
+                        .cast_unsigned(),
                     random: challenge.nonce.to_vec(),
                 })
             }

server/crates/arbiter-server/src/grpc/operator.rs

@@ -1,11 +1,10 @@
 use crate::{
     grpc::request_tracker::RequestTracker,
-    peers::operator::{OutOfBand, OperatorConnection, OperatorSession},
+    peers::operator::{OperatorConnection, OperatorSession, OutOfBand},
 };
 use arbiter_proto::{
     proto::operator::{
-        OperatorRequest, OperatorResponse,
+        OperatorRequest, OperatorResponse, operator_request::Payload as OperatorRequestPayload,
-        operator_request::Payload as OperatorRequestPayload,
         operator_response::Payload as OperatorResponsePayload,
     },
     transport::{Error as TransportError, Receiver, Sender, grpc::GrpcBi},
@@ -111,6 +110,9 @@ async fn dispatch_inner(
         OperatorRequestPayload::Vault(req) => vault::dispatch(actor, req).await,
         OperatorRequestPayload::Evm(req) => evm::dispatch(actor, req).await,
         OperatorRequestPayload::SdkClient(req) => sdk_client::dispatch(actor, req).await,
+        OperatorRequestPayload::Governance(_) => {
+            Err(Status::permission_denied(stringify!(Governance)))
+        }
         OperatorRequestPayload::Auth(..) => {
             warn!("Unsupported post-auth operator auth request");
             Err(Status::invalid_argument("Unsupported operator request"))

server/crates/arbiter-server/src/grpc/operator/auth.rs

@@ -80,7 +80,7 @@ impl Sender<Result<auth::Outbound, auth::Error>> for AuthTransportAdapter<'_> {
                         .timestamp
                         .timestamp_nanos_opt()
                         .expect("timestamp within range")
-                        as u64,
+                        .cast_unsigned(),
                     random: challenge.nonce.to_vec(),
                 })
             }
@@ -171,7 +171,7 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
 
                 Some(auth::Inbound::AuthChallengeRequest {
                     pubkey,
-                    bootstrap_token,
+                    bootstrap_token: bootstrap_token.map(String::into_bytes),
                 })
             }
             AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution { signature }) => {

server/crates/arbiter-server/src/grpc/operator/evm.rs

@@ -217,6 +217,11 @@ async fn handle_sign_transaction(
                 result: Some(vet_error.convert()),
             }
         }
+        Err(kameo::error::SendError::HandlerError(
+            SessionSignTransactionError::ClientNotConnected,
+        )) => {
+            return Err(Status::permission_denied("client not connected"));
+        }
         Err(kameo::error::SendError::HandlerError(SessionSignTransactionError::Internal)) => {
             EvmSignTransactionResponse {
                 result: Some(EvmSignTransactionResult::Error(

server/crates/arbiter-server/src/grpc/operator/inbound.rs

@@ -86,6 +86,7 @@ impl TryConvert for ProtoSharedSettings {
                 .valid_until
                 .map(ProtoTimestamp::try_convert)
                 .transpose()?,
+            revoked_at: None,
             max_gas_fee_per_gas: self
                 .max_gas_fee_per_gas
                 .as_deref()

server/crates/arbiter-server/src/grpc/operator/vault.rs

@@ -3,7 +3,6 @@ use crate::{
     peers::operator::{OperatorSession, session::handlers::HandleQueryVaultState},
 };
 use arbiter_proto::{
-    proto::shared::VaultState as ProtoVaultState,
     proto::operator::{
         operator_response::Payload as OperatorResponsePayload,
         vault::{
@@ -11,6 +10,7 @@ use arbiter_proto::{
             response::Payload as VaultResponsePayload,
         },
     },
+    proto::shared::VaultState as ProtoVaultState,
 };
 
 use kameo::actor::ActorRef;
@@ -33,11 +33,11 @@ pub(super) async fn dispatch(
 
     match payload {
         VaultRequestPayload::QueryState(()) => handle_query_vault_state(actor).await,
-        VaultRequestPayload::Unseal(_) | VaultRequestPayload::Bootstrap(_) => {
+        VaultRequestPayload::Unseal(_)
-            Err(Status::permission_denied(
+        | VaultRequestPayload::Bootstrap(_)
+        | VaultRequestPayload::Rekey(_) => Err(Status::permission_denied(
             "Vault is already unsealed; unseal/bootstrap not permitted in session",
-            ))
+        )),
-        }
     }
 }
 

server/crates/arbiter-server/src/grpc/operator/vault_gate/inbound.rs

@@ -1,14 +1,17 @@
 use crate::{
+    crypto::shamir,
     grpc::{Convert, TryConvert},
     peers::operator::vault_gate::{
-        self as vault_gate, HandleBootstrapEncryptedKey, HandleHandshake, HandleUnsealEncryptedKey,
+        self as vault_gate, HandleBootstrapEncryptedKey, HandleContributeBootstrapPassphrase,
+        HandleContributeUnsealPassphrase, HandleDeclareCommittee, HandleHandshake,
+        HandleUnsealEncryptedKey,
     },
 };
 use arbiter_proto::proto::operator::{
     operator_request::Payload as OperatorRequestPayload,
     vault::{
         self as proto_vault,
-        bootstrap::{self as proto_bootstrap},
+        bootstrap::{self as proto_bootstrap, request::Payload as BootstrapRequestPayload},
         request::Payload as VaultRequestPayload,
         unseal::{self as proto_unseal, request::Payload as UnsealRequestPayload},
     },
@@ -50,6 +53,7 @@ impl TryConvert for VaultRequestPayload {
             Self::QueryState(()) => Ok(vault_gate::Inbound::HandleVaultState),
             Self::Unseal(req) => req.try_convert(),
             Self::Bootstrap(req) => req.try_convert(),
+            Self::Rekey(_) => Err(Status::unimplemented("Vault re-key is not available")),
         }
     }
 }
@@ -73,6 +77,16 @@ impl TryConvert for UnsealRequestPayload {
         match self {
             Self::Start(start) => start.try_convert(),
             Self::EncryptedKey(key) => Ok(key.convert()),
+            Self::ContributePassphrase(passphrase) => {
+                Ok(vault_gate::Inbound::HandleContributeUnsealPassphrase(
+                    HandleContributeUnsealPassphrase {
+                        passphrase: passphrase.passphrase,
+                    },
+                ))
+            }
+            Self::ContributeRecoveryPassphrase(_) => Err(Status::unimplemented(
+                "Recovery operator contributions are not available",
+            )),
         }
     }
 }
@@ -107,12 +121,52 @@ impl TryConvert for proto_bootstrap::Request {
     type Error = Status;
 
     fn try_convert(self) -> Result<vault_gate::Inbound, Status> {
-        self.encrypted_key
+        self.payload
-            .ok_or_else(|| Status::invalid_argument("Missing bootstrap encrypted key"))?
+            .ok_or_else(|| Status::invalid_argument("Missing bootstrap payload"))?
             .try_convert()
     }
 }
 
+impl TryConvert for BootstrapRequestPayload {
+    type Output = vault_gate::Inbound;
+    type Error = Status;
+
+    fn try_convert(self) -> Result<vault_gate::Inbound, Status> {
+        match self {
+            Self::EncryptedKey(key) => key.try_convert(),
+            Self::DeclareCommittee(dc) => {
+                if dc.recovery_count != 0 {
+                    return Err(Status::unimplemented(
+                        "Recovery operator contributions are not available",
+                    ));
+                }
+                let count = usize::try_from(dc.count)
+                    .ok()
+                    .filter(|count| *count <= shamir::MAX_COMMITTEE_SIZE)
+                    .ok_or_else(|| {
+                        Status::invalid_argument(format!(
+                            "Committee count must not exceed {}",
+                            shamir::MAX_COMMITTEE_SIZE
+                        ))
+                    })?;
+                Ok(vault_gate::Inbound::HandleDeclareCommittee(
+                    HandleDeclareCommittee { count },
+                ))
+            }
+            Self::ContributePassphrase(cp) => {
+                Ok(vault_gate::Inbound::HandleContributeBootstrapPassphrase(
+                    HandleContributeBootstrapPassphrase {
+                        passphrase: cp.passphrase,
+                    },
+                ))
+            }
+            Self::ContributeRecoveryPassphrase(_) => Err(Status::unimplemented(
+                "Recovery operator contributions are not available",
+            )),
+        }
+    }
+}
+
 impl TryConvert for proto_bootstrap::BootstrapEncryptedKey {
     type Output = vault_gate::Inbound;
     type Error = Status;

server/crates/arbiter-server/src/grpc/operator/vault_gate/outbound.rs

@@ -1,10 +1,9 @@
 use crate::{
-    actors::vault::VaultState,
+    actors::{vault::VaultState, vault_coordinator},
     grpc::{Convert, TryConvert},
     peers::operator::vault_gate::{self as vault_gate},
 };
 use arbiter_proto::proto::{
-    shared::VaultState as ProtoVaultState,
     operator::{
         operator_response::Payload as OperatorResponsePayload,
         vault::{
@@ -17,6 +16,7 @@ use arbiter_proto::proto::{
             },
         },
     },
+    shared::VaultState as ProtoVaultState,
 };
 
 use tonic::Status;
@@ -34,6 +34,26 @@ const fn wrap_unseal_response(payload: UnsealResponsePayload) -> OperatorRespons
     }))
 }
 
+/// Ceremony errors are the operator's own doing far more often than ours, so
+/// they travel back as a specific status instead of a blanket internal error.
+fn ceremony_status(error: &vault_coordinator::Error) -> Status {
+    match error {
+        vault_coordinator::Error::AlreadyBootstrapping
+        | vault_coordinator::Error::AlreadyUnsealing
+        | vault_coordinator::Error::NotBootstrapping
+        | vault_coordinator::Error::DuplicateContribution => {
+            Status::failed_precondition(error.to_string())
+        }
+        vault_coordinator::Error::EmptyCommittee
+        | vault_coordinator::Error::UnsupportedCommittee
+        | vault_coordinator::Error::CommitteeTooLarge => {
+            Status::invalid_argument(error.to_string())
+        }
+        vault_coordinator::Error::InvalidPassphrase => Status::unauthenticated(error.to_string()),
+        _ => Status::internal("Vault ceremony failed"),
+    }
+}
+
 fn wrap_bootstrap_response(result: ProtoBootstrapResult) -> OperatorResponsePayload {
     wrap_vault_response(VaultResponsePayload::Bootstrap(proto_bootstrap::Response {
         result: result.into(),
@@ -110,6 +130,56 @@ impl TryConvert for vault_gate::Outbound {
                 };
                 Ok(wrap_bootstrap_response(proto_result))
             }
+            Self::HandleDeclareCommittee(result) => {
+                let proto_result = match result {
+                    Ok(()) => ProtoBootstrapResult::AwaitingContributions,
+                    Err(vault_gate::Error::Ceremony(
+                        vault_coordinator::Error::AlreadyBootstrapped,
+                    )) => ProtoBootstrapResult::AlreadyBootstrapped,
+                    Err(vault_gate::Error::Ceremony(err)) => {
+                        warn!(?err, "declare committee failed");
+                        return Err(ceremony_status(&err));
+                    }
+                    Err(err) => {
+                        warn!(?err, "declare committee failed");
+                        return Err(Status::internal("Failed to declare committee"));
+                    }
+                };
+                Ok(wrap_bootstrap_response(proto_result))
+            }
+            Self::HandleContributeBootstrapPassphrase(result) => {
+                let proto_result = match result {
+                    Ok(true) => ProtoBootstrapResult::Success,
+                    Ok(false) => ProtoBootstrapResult::AwaitingContributions,
+                    Err(vault_gate::Error::Ceremony(
+                        vault_coordinator::Error::AlreadyBootstrapped,
+                    )) => ProtoBootstrapResult::AlreadyBootstrapped,
+                    Err(vault_gate::Error::Ceremony(err)) => {
+                        warn!(?err, "contribute bootstrap passphrase failed");
+                        return Err(ceremony_status(&err));
+                    }
+                    Err(err) => {
+                        warn!(?err, "contribute bootstrap passphrase failed");
+                        return Err(Status::internal(
+                            "Failed to contribute bootstrap passphrase",
+                        ));
+                    }
+                };
+                Ok(wrap_bootstrap_response(proto_result))
+            }
+            Self::HandleContributeUnsealPassphrase(result) => {
+                let proto_result = match result {
+                    Ok(true) => ProtoUnsealResult::Success,
+                    Ok(false) => ProtoUnsealResult::AwaitingContributions,
+                    Err(err) => {
+                        warn!(?err, "contribute unseal passphrase failed");
+                        return Err(Status::internal("Failed to contribute unseal passphrase"));
+                    }
+                };
+                Ok(wrap_unseal_response(UnsealResponsePayload::Result(
+                    proto_result.into(),
+                )))
+            }
         }
     }
 }

server/crates/arbiter-server/src/peers/client/auth.rs

@@ -8,7 +8,7 @@ use crate::{
     crypto::integrity::{self, AttestationStatus},
     db::{
         self,
-        models::{ProgramClientMetadata, SqliteTimestamp},
+        models::ProgramClientMetadata,
         schema::program_client,
     },
 };
@@ -18,14 +18,13 @@ use arbiter_proto::{
     transport::{Bi, expect_message},
 };
 
-use chrono::Utc;
 use diesel::{
     ExpressionMethods as _, OptionalExtension as _, QueryDsl as _, SelectableHelper as _,
-    dsl::insert_into, update,
+    dsl::insert_into,
 };
 use diesel_async::RunQueryDsl as _;
 use kameo::{actor::ActorRef, error::SendError};
-use tracing::error;
+use tracing::{error, warn};
 
 #[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
 pub enum Error {
@@ -211,71 +210,47 @@ async fn insert_client(
     .await
 }
 
-async fn sync_client_metadata(
+/// Compares stored metadata against what a reconnecting client presents.
+/// Metadata is frozen after initial operator approval and must not be silently
+/// overwritten. Doing so would let an approved client forge its displayed
+/// identity in later approval prompts. Drift is logged and ignored.
+async fn check_metadata_drift(
     db: &db::DatabasePool,
     client_id: i32,
-    metadata: &ClientMetadata,
+    presented: &ClientMetadata,
 ) -> Result<(), Error> {
-    use crate::db::schema::{client_metadata, client_metadata_history};
+    use crate::db::schema::client_metadata;
-
-    let now = SqliteTimestamp(Utc::now());
 
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
         Error::DatabasePoolUnavailable
     })?;
 
-    conn.exclusive_transaction(async |conn| {
+    let current: ProgramClientMetadata = program_client::table
-        let (current_metadata_id, current): (i32, ProgramClientMetadata) = program_client::table
         .find(client_id)
         .inner_join(client_metadata::table)
-            .select((
+        .select(ProgramClientMetadata::as_select())
-                program_client::metadata_id,
+        .first(&mut conn)
-                ProgramClientMetadata::as_select(),
-            ))
-            .first(&mut *conn)
-            .await?;
-
-        let unchanged = current.name == metadata.name
-            && current.description == metadata.description
-            && current.version == metadata.version;
-        if unchanged {
-            return Ok(());
-        }
-
-        insert_into(client_metadata_history::table)
-            .values((
-                client_metadata_history::metadata_id.eq(current_metadata_id),
-                client_metadata_history::client_id.eq(client_id),
-            ))
-            .execute(&mut *conn)
-            .await?;
-
-        let metadata_id = insert_into(client_metadata::table)
-            .values((
-                client_metadata::name.eq(&metadata.name),
-                client_metadata::description.eq(&metadata.description),
-                client_metadata::version.eq(&metadata.version),
-            ))
-            .returning(client_metadata::id)
-            .get_result::<i32>(&mut *conn)
-            .await?;
-
-        update(program_client::table.find(client_id))
-            .set((
-                program_client::metadata_id.eq(metadata_id),
-                program_client::updated_at.eq(now),
-            ))
-            .execute(&mut *conn)
-            .await?;
-
-        Ok::<(), diesel::result::Error>(())
-    })
         .await
         .map_err(|e| {
             error!(error = ?e, "Database error");
             Error::DatabaseOperationFailed
-    })
+        })?;
+
+    let changed = current.name != presented.name
+        || current.description != presented.description
+        || current.version != presented.version;
+
+    if changed {
+        warn!(
+            client_id,
+            stored_name = %current.name,
+            presented_name = %presented.name,
+            "reconnecting client presented different metadata; ignoring - metadata is frozen after operator approval"
+        );
+    }
+
+    Ok(())
 }
 
 async fn challenge_client<T>(
@@ -298,7 +273,7 @@ where
 
     let signature = expect_message(transport, |req: Inbound| match req {
         Inbound::AuthChallengeSolution { signature } => Some(signature),
-        _ => None,
+        Inbound::AuthChallengeRequest { .. } => None,
     })
     .await
     .map_err(|e| {
@@ -324,6 +299,7 @@ where
 
     let client_id = if let Some(id) = get_client_id(&props.db, &pubkey).await? {
         verify_integrity(&props.db, &props.actors.vault, &pubkey).await?;
+        check_metadata_drift(&props.db, id, &metadata).await?;
         id
     } else {
         approve_new_client(
@@ -337,8 +313,6 @@ where
         insert_client(&props.db, &props.actors.vault, &pubkey, &metadata).await?
     };
 
-    sync_client_metadata(&props.db, client_id, &metadata).await?;
-
     let challenge = AuthChallenge::generate(&mut rand::rng());
     challenge_client(transport, pubkey, challenge).await?;
 

server/crates/arbiter-server/src/peers/client/session.rs

@@ -83,7 +83,7 @@ impl Actor for ClientSession {
         args.props
             .actors
             .flow_coordinator
-            .ask(RegisterClient { actor: this })
+            .ask(RegisterClient { client_id: args.client_id, actor: this })
             .await
             .map_err(|_| Error::ConnectionRegistrationFailed)?;
         Ok(args)

server/crates/arbiter-server/src/peers/operator/auth/mod.rs

@@ -14,7 +14,7 @@ mod state;
 pub enum Inbound {
     AuthChallengeRequest {
         pubkey: authn::PublicKey,
-        bootstrap_token: Option<String>,
+        bootstrap_token: Option<Vec<u8>>,
     },
     AuthChallengeSolution {
         signature: Vec<u8>,

server/crates/arbiter-server/src/peers/operator/auth/state.rs

@@ -3,8 +3,8 @@ use super::{
     Error,
 };
 use crate::{
-    actors::bootstrap::ConsumeToken,
+    actors::bootstrap::VerifyToken,
-    db::{DatabasePool, schema::operator_identity},
+    db::{DatabasePool, models::OperatorId, schema::operator_identity},
     peers::operator::auth::Outbound,
 };
 use arbiter_crypto::authn::{self, AuthChallenge, OPERATOR_CONTEXT};
@@ -16,13 +16,12 @@ use tracing::error;
 
 pub(super) struct ChallengeRequest {
     pub(super) pubkey: authn::PublicKey,
-    pub(super) bootstrap_token: Option<String>,
+    pub(super) bootstrap_token: Option<Vec<u8>>,
 }
 
-pub(super) struct ChallengeContext {
+pub struct ChallengeContext {
     pub(super) challenge: AuthChallenge,
     pub(super) pubkey: authn::PublicKey,
-    pub(super) bootstrap_token: Option<String>,
 }
 
 pub(super) struct ChallengeSolution {
@@ -38,7 +37,10 @@ smlang::statemachine!(
     }
 );
 
-async fn get_client_id(db: &DatabasePool, pubkey: &authn::PublicKey) -> Result<Option<i32>, Error> {
+async fn get_client_id(
+    db: &DatabasePool,
+    pubkey: &authn::PublicKey,
+) -> Result<Option<OperatorId>, Error> {
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
         Error::internal("Database unavailable")
@@ -47,7 +49,7 @@ async fn get_client_id(db: &DatabasePool, pubkey: &authn::PublicKey) -> Result<O
     operator_identity::table
         .filter(operator_identity::public_key.eq(pubkey.to_bytes()))
         .select(operator_identity::id)
-        .first::<i32>(&mut conn)
+        .first::<OperatorId>(&mut conn)
         .await
         .optional()
         .map_err(|e| {
@@ -56,14 +58,14 @@ async fn get_client_id(db: &DatabasePool, pubkey: &authn::PublicKey) -> Result<O
         })
 }
 
-async fn register_key(db: &DatabasePool, pubkey: &authn::PublicKey) -> Result<i32, Error> {
+async fn register_key(db: &DatabasePool, pubkey: &authn::PublicKey) -> Result<OperatorId, Error> {
     let pubkey_bytes = pubkey.to_bytes();
     let mut conn = db.get().await.map_err(|e| {
         error!(error = ?e, "Database pool error");
         Error::internal("Database unavailable")
     })?;
 
-    let id: i32 = diesel::insert_into(operator_identity::table)
+    let id: OperatorId = diesel::insert_into(operator_identity::table)
         .values((operator_identity::public_key.eq(pubkey_bytes),))
         .returning(operator_identity::id)
         .get_result(&mut conn)
@@ -79,11 +81,16 @@ async fn register_key(db: &DatabasePool, pubkey: &authn::PublicKey) -> Result<i3
 pub(super) struct AuthContext<'a, T: ?Sized> {
     pub(super) conn: &'a mut OperatorConnection,
     pub(super) transport: &'a mut T,
+    bootstrap_token: Option<Vec<u8>>,
 }
 
 impl<'a, T: ?Sized> AuthContext<'a, T> {
     pub(super) const fn new(conn: &'a mut OperatorConnection, transport: &'a mut T) -> Self {
-        Self { conn, transport }
+        Self {
+            conn,
+            transport,
+            bootstrap_token: None,
+        }
     }
 }
 
@@ -108,6 +115,8 @@ where
             }
         }
 
+        self.bootstrap_token = bootstrap_token;
+
         let challenge = AuthChallenge::generate(&mut rand::rng());
 
         self.transport
@@ -120,22 +129,12 @@ where
                 Error::Transport
             })?;
 
-        Ok(ChallengeContext {
+        Ok(ChallengeContext { challenge, pubkey })
-            challenge,
-            pubkey,
-            bootstrap_token,
-        })
     }
 
-    #[allow(missing_docs)]
-    #[allow(clippy::unused_unit)]
     async fn verify_solution(
         &mut self,
-        ChallengeContext {
+        ChallengeContext { challenge, pubkey }: &ChallengeContext,
-            challenge,
-            pubkey,
-            bootstrap_token,
-        }: &ChallengeContext,
         ChallengeSolution { solution }: ChallengeSolution,
     ) -> Result<Credentials, Self::Error> {
         let signature = authn::Signature::try_from(solution.as_slice()).map_err(|()| {
@@ -154,15 +153,13 @@ where
         }
 
         // Resolve client id: bootstrap (consume token + register) or lookup
-        let id = match bootstrap_token {
+        let id = match self.bootstrap_token.take() {
             Some(token) => {
                 let token_ok: bool = self
                     .conn
                     .actors
                     .bootstrapper
-                    .ask(ConsumeToken {
+                    .ask(VerifyToken { token })
-                        token: token.clone(),
-                    })
                     .await
                     .map_err(|e| {
                         error!(?e, "Failed to consume bootstrap token");

server/crates/arbiter-server/src/peers/operator/mod.rs

@@ -4,7 +4,7 @@ use crate::{
         vault::{GetState, Vault},
     },
     crypto::integrity::{self, AttestationStatus, Integrable},
-    db::{DatabaseError, DatabasePool},
+    db::{DatabaseError, DatabasePool, models::OperatorId},
     peers::client::ClientProfile,
 };
 use arbiter_crypto::authn;
@@ -25,7 +25,7 @@ pub mod vault_gate;
 
 #[derive(Debug, Clone, Hashable)]
 pub struct Credentials {
-    pub id: i32,
+    pub id: OperatorId,
     pub pubkey: authn::PublicKey,
 }
 

server/crates/arbiter-server/src/peers/operator/session/handlers.rs

@@ -5,12 +5,15 @@ use crate::{
             ClientSignTransaction, Generate, ListWallets, OperatorCreateGrant, OperatorListGrants,
             SignTransactionError as EvmSignError,
         },
-        flow_coordinator::client_connect_approval::ClientApprovalAnswer,
+        flow_coordinator::{IsClientConnected, client_connect_approval::ClientApprovalAnswer},
         vault::VaultState,
     },
-    db::models::{
+    db::{
+        models::{
             EvmWalletAccess, EvmWalletId, NewEvmWalletAccess, ProgramClient, ProgramClientMetadata,
         },
+        schema::program_client,
+    },
     evm::policies::{Grant, SpecificGrant},
 };
 use arbiter_crypto::authn;
@@ -19,13 +22,16 @@ use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
 use diesel::{ExpressionMethods as _, QueryDsl as _, SelectableHelper};
 use diesel_async::{AsyncConnection, RunQueryDsl};
 use kameo::{error::SendError, messages, prelude::Context};
-use tracing::error;
+use tracing::{error, info, warn};
 
 #[derive(Debug, Error)]
 pub enum SignTransactionError {
     #[error("Policy evaluation failed")]
     Vet(#[from] crate::evm::VetError),
 
+    #[error("Client not connected")]
+    ClientNotConnected,
+
     #[error("Internal signing error")]
     Internal,
 }
@@ -147,6 +153,30 @@ impl OperatorSession {
         wallet_address: Address,
         transaction: TxEip1559,
     ) -> Result<Signature, SignTransactionError> {
+        if !self.approved_client_ids.contains(&client_id) {
+            warn!(
+                client_id,
+                "operator attempted to sign for client not in its approved set"
+            );
+            return Err(SignTransactionError::ClientNotConnected);
+        }
+
+        let connected = self
+            .props
+            .actors
+            .flow_coordinator
+            .ask(IsClientConnected { client_id })
+            .await
+            .unwrap_or(false);
+
+        if !connected {
+            self.approved_client_ids.remove(&client_id);
+            warn!(client_id, "operator attempted to sign for disconnected client");
+            return Err(SignTransactionError::ClientNotConnected);
+        }
+
+        info!(client_id, event = "sign_transaction", "operator.sign_transaction");
+
         match self
             .props
             .actors
@@ -202,7 +232,7 @@ impl OperatorSession {
             use crate::db::schema::evm_wallet_access;
             for entry in entries {
                 diesel::delete(evm_wallet_access::table)
-                    .filter(evm_wallet_access::wallet_id.eq(entry))
+                    .filter(evm_wallet_access::id.eq(entry))
                     .execute(&mut *conn)
                     .await?;
             }
@@ -218,8 +248,7 @@ impl OperatorSession {
         &mut self,
     ) -> Result<Vec<EvmWalletAccess>, Error> {
         let mut conn = self.props.db.get().await?;
-        use crate::db::schema::evm_wallet_access;
+        let access_entries = crate::db::schema::evm_wallet_access::table
-        let access_entries = evm_wallet_access::table
             .select(EvmWalletAccess::as_select())
             .load::<_>(&mut conn)
             .await?;
@@ -256,6 +285,30 @@ impl OperatorSession {
 
         ctx.actor_ref().unlink(&pending_approval.controller).await;
 
+        if approved {
+            let pubkey_bytes = pending_approval.pubkey.to_bytes();
+            match self.props.db.get().await {
+                Ok(mut conn) => {
+                    match program_client::table
+                        .filter(program_client::public_key.eq(pubkey_bytes.as_slice()))
+                        .select(program_client::id)
+                        .first::<i32>(&mut conn)
+                        .await
+                    {
+                        Ok(client_id) => {
+                            self.approved_client_ids.insert(client_id);
+                        }
+                        Err(err) => {
+                            error!(?err, "Failed to look up client_id for approved pubkey");
+                        }
+                    }
+                }
+                Err(err) => {
+                    error!(?err, "DB pool error after client approval");
+                }
+            }
+        }
+
         Ok(())
     }
 
@@ -278,3 +331,142 @@ impl OperatorSession {
         Ok(clients)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::db::{self, models::{EvmWalletId, NewEvmWalletAccess}, schema::evm_wallet_access};
+    use diesel::{ExpressionMethods as _, QueryDsl as _, SelectableHelper};
+    use diesel_async::{AsyncConnection, RunQueryDsl};
+
+    /// Regression test: revocation must delete by access-entry `id`, not by `wallet_id`.
+    ///
+    /// Before the fix, revoking `entry_id=1` would delete all rows where `wallet_id=1`,
+    /// wiping out every client's access to wallet #1.
+    #[tokio::test]
+    async fn revoke_deletes_by_entry_id_not_wallet_id() {
+        use crate::db::models::EvmWalletAccess;
+
+        let pool = db::create_test_pool().await;
+        let mut conn = pool.get().await.expect("pool connection");
+
+        // Insert two access entries for the same wallet but different clients.
+        // entry A: id will be 1, wallet_id=1, client_id=10
+        // entry B: id will be 2, wallet_id=1, client_id=20
+        let entry_a = diesel::insert_into(evm_wallet_access::table)
+            .values(NewEvmWalletAccess {
+                wallet_id: EvmWalletId::from_raw(1),
+                client_id: 10,
+            })
+            .returning(EvmWalletAccess::as_select())
+            .get_result(&mut *conn)
+            .await
+            .expect("insert entry A");
+
+        let entry_b = diesel::insert_into(evm_wallet_access::table)
+            .values(NewEvmWalletAccess {
+                wallet_id: EvmWalletId::from_raw(1),
+                client_id: 20,
+            })
+            .returning(EvmWalletAccess::as_select())
+            .get_result(&mut *conn)
+            .await
+            .expect("insert entry B");
+
+        // Revoke only entry A by its primary key id.
+        conn.transaction(async |conn| {
+            diesel::delete(evm_wallet_access::table)
+                .filter(evm_wallet_access::id.eq(entry_a.id))
+                .execute(&mut *conn)
+                .await
+        })
+        .await
+        .expect("revoke entry A");
+
+        // Entry A must be gone.
+        let gone = evm_wallet_access::table
+            .filter(evm_wallet_access::id.eq(entry_a.id))
+            .count()
+            .get_result::<i64>(&mut *conn)
+            .await
+            .expect("count entry A");
+        assert_eq!(gone, 0, "revoked entry must be deleted");
+
+        // Entry B (same wallet, different client) must still exist.
+        let still_there = evm_wallet_access::table
+            .filter(evm_wallet_access::id.eq(entry_b.id))
+            .count()
+            .get_result::<i64>(&mut *conn)
+            .await
+            .expect("count entry B");
+        assert_eq!(still_there, 1, "unrelated entry must not be deleted");
+    }
+
+    /// Regression test: when `entry_id` and `wallet_id` differ, only the correct row is removed.
+    ///
+    /// This specifically catches the case where `entry.id=5` and `wallet_id=1` are different values;
+    /// the old bug would delete by `wallet_id`, potentially matching a completely different entry.
+    #[tokio::test]
+    async fn revoke_with_mismatched_wallet_and_entry_ids() {
+        use crate::db::models::EvmWalletAccess;
+
+        let pool = db::create_test_pool().await;
+        let mut conn = pool.get().await.expect("pool connection");
+
+        // Insert entries to force auto-increment IDs to diverge from wallet_ids.
+        // We'll insert 5 placeholder entries first so that the real entry gets id=6.
+        for i in 1_i32..=5 {
+            diesel::insert_into(evm_wallet_access::table)
+                .values(NewEvmWalletAccess {
+                    wallet_id: EvmWalletId::from_raw(99),
+                    client_id: i,
+                })
+                .execute(&mut *conn)
+                .await
+                .expect("insert placeholder");
+        }
+
+        // Real target: wallet_id=1, will get id=6.
+        let target = diesel::insert_into(evm_wallet_access::table)
+            .values(NewEvmWalletAccess {
+                wallet_id: EvmWalletId::from_raw(1),
+                client_id: 1,
+            })
+            .returning(EvmWalletAccess::as_select())
+            .get_result(&mut *conn)
+            .await
+            .expect("insert target");
+
+        // Sanity: target.id != target.wallet_id
+        assert_ne!(
+            target.id, target.wallet_id.to_raw(),
+            "test prerequisite: id and wallet_id must differ"
+        );
+
+        // Revoke by entry id.
+        conn.transaction(async |conn| {
+            diesel::delete(evm_wallet_access::table)
+                .filter(evm_wallet_access::id.eq(target.id))
+                .execute(&mut *conn)
+                .await
+        })
+        .await
+        .expect("revoke target");
+
+        let remaining = evm_wallet_access::table
+            .filter(evm_wallet_access::id.eq(target.id))
+            .count()
+            .get_result::<i64>(&mut *conn)
+            .await
+            .expect("count target");
+        assert_eq!(remaining, 0, "target must be deleted by its entry id");
+
+        // Placeholders for wallet_id=99 must be untouched.
+        let placeholders = evm_wallet_access::table
+            .filter(evm_wallet_access::wallet_id.eq(99))
+            .count()
+            .get_result::<i64>(&mut *conn)
+            .await
+            .expect("count placeholders");
+        assert_eq!(placeholders, 5, "unrelated entries must survive");
+    }
+}

server/crates/arbiter-server/src/peers/operator/session/mod.rs

@@ -1,16 +1,14 @@
 use super::{OutOfBand, OperatorConnection};
 use crate::{
     actors::{
-        flow_coordinator::client_connect_approval::ClientApprovalController,
+        flow_coordinator::{GetConnectedClientIds, client_connect_approval::{ClientApprovalAnswer, ClientApprovalController}}, operator_registry::ConnectOperator,
-        operator_registry::ConnectOperator,
+    }, peers::client::ClientProfile,
-    },
-    peers::client::ClientProfile,
 };
 use arbiter_crypto::authn;
 use arbiter_proto::transport::Sender;
 
 use kameo::{Actor, actor::ActorRef, messages};
-use std::{borrow::Cow, collections::HashMap};
+use std::{borrow::Cow, collections::{HashMap, HashSet}};
 use thiserror::Error;
 use tracing::error;
 
@@ -54,6 +52,10 @@ pub struct OperatorSession {
     sender: Box<dyn Sender<OutOfBand>>,
 
     pending_client_approvals: HashMap<Vec<u8>, PendingClientApproval>,
+    /// DB `client_ids` this operator session is allowed to sign for.
+    /// Seeded from currently-connected clients on start, then updated as
+    /// approvals are granted or denied during the session lifetime.
+    approved_client_ids: HashSet<i32>,
 }
 
 pub mod handlers;
@@ -63,7 +65,8 @@ impl OperatorSession {
         Self {
             props,
             sender,
-            pending_client_approvals: Default::default(),
+            pending_client_approvals: HashMap::default(),
+            approved_client_ids: HashSet::default(),
         }
     }
 }
@@ -88,6 +91,7 @@ impl OperatorSession {
                 actor = "operator",
                 event = "failed to announce new client connection"
             );
+            let _ = controller.tell(ClientApprovalAnswer { approved: false }).await;
             return;
         }
 
@@ -106,7 +110,7 @@ impl Actor for OperatorSession {
 
     type Error = Error;
 
-    async fn on_start(args: Self::Args, this: ActorRef<Self>) -> Result<Self, Self::Error> {
+    async fn on_start(mut args: Self::Args, this: ActorRef<Self>) -> Result<Self, Self::Error> {
         args.props
             .actors
             .operator_registry
@@ -121,6 +125,16 @@ impl Actor for OperatorSession {
                 );
                 Error::internal("Failed to register operator connection with operator registry")
             })?;
+
+        // Seed approved set with clients already connected when this session starts.
+        // New clients will be added via handle_new_client_approve as they are approved.
+        match args.props.actors.flow_coordinator.ask(GetConnectedClientIds {}).await {
+            Ok(ids) => args.approved_client_ids.extend(ids),
+            Err(err) => {
+                error!(?err, "Failed to fetch connected client IDs on operator session start");
+            }
+        }
+
         Ok(args)
     }
 

server/crates/arbiter-server/src/peers/operator/vault_gate/mod.rs

@@ -3,8 +3,9 @@ use crate::{
     actors::{
         GlobalActors,
         vault::{self, Bootstrap, GetState, TryUnseal, VaultState, events},
+        vault_coordinator::{self, ContributeBootstrap, ContributeUnseal, StartBootstrap},
     },
-    crypto::integrity::{self},
+    crypto::{KeyCell, integrity},
     db::DatabasePool,
 };
 use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
@@ -25,17 +26,29 @@ pub enum Error {
     AlreadyBootstrapped,
     #[error("Invalid key provided")]
     InvalidKey,
-
+    #[error("Vault locked: too many failed unseal attempts")]
+    LockedOut,
     #[error("State transition failed")]
     State,
-
+    #[error("Vault ceremony failed: {0}")]
+    Ceremony(#[from] vault_coordinator::Error),
     #[error("Internal error: {0}")]
     Internal(String),
 }
+
 impl Error {
     fn internal(message: impl Into<String>) -> Self {
         Self::Internal(message.into())
     }
+
+    /// Preserve the coordinator's own error so the operator learns why a
+    /// ceremony was refused instead of reading "internal error".
+    fn ceremony<M>(error: SendError<M, vault_coordinator::Error>) -> Self {
+        match error {
+            SendError::HandlerError(inner) => Self::Ceremony(inner),
+            _ => Self::internal("VaultCoordinator unavailable"),
+        }
+    }
 }
 
 pub struct HandshakeResponse {
@@ -69,7 +82,6 @@ impl VaultGate {
 
 impl Actor for VaultGate {
     type Args = Self;
-
     type Error = ();
 
     async fn on_start(
@@ -100,11 +112,8 @@ impl VaultGate {
         associated_data: &[u8],
     ) -> Result<SafeCell<Vec<u8>>, ()> {
         let nonce = XNonce::from_slice(nonce);
-
         let cipher = XChaCha20Poly1305::new(secret.as_bytes().into());
-
         let mut key_buffer = SafeCell::new(ciphertext.to_vec());
-
         let decryption_result = key_buffer.write_inline(|write_handle| {
             cipher.decrypt_in_place(nonce, associated_data, write_handle)
         });
@@ -117,9 +126,13 @@ impl VaultGate {
             }
         }
     }
+
+    fn key_cell(buffer: SafeCell<Vec<u8>>) -> Result<KeyCell, Error> {
+        KeyCell::try_from(buffer).map_err(|()| Error::InvalidKey)
+    }
 }
 
-#[messages(messages = Inbound, replies = Outbound)]
+#[messages]
 impl VaultGate {
     #[message]
     pub fn handle_handshake(
@@ -128,14 +141,11 @@ impl VaultGate {
     ) -> Result<HandshakeResponse, Error> {
         let ephemeral_secret = EphemeralSecret::random();
         let public_key = PublicKey::from(&ephemeral_secret);
-
         let secret = ephemeral_secret.diffie_hellman(&client_pubkey);
-
         self.state = State::ReadyForExchange {
             server_key: public_key,
             secret,
         };
-
         Ok(HandshakeResponse {
             server_pubkey: public_key,
         })
@@ -151,25 +161,17 @@ impl VaultGate {
         let State::ReadyForExchange { secret, .. } = &self.state else {
             return Err(Error::State);
         };
+        let seal_key = Self::decrypt_key(secret, &nonce, &ciphertext, &associated_data)
+            .map_err(|()| Error::InvalidKey)
+            .and_then(Self::key_cell)?;
 
-        let Ok(seal_key_buffer) = Self::decrypt_key(secret, &nonce, &ciphertext, &associated_data)
+        match self.actors.vault.ask(TryUnseal { seal_key }).await {
-        else {
-            return Err(Error::InvalidKey);
-        };
-
-        match self
-            .actors
-            .vault
-            .ask(TryUnseal {
-                seal_key_raw: seal_key_buffer,
-            })
-            .await
-        {
             Ok(()) => {
                 info!("Successfully unsealed key with client-provided key");
                 Ok(())
             }
             Err(SendError::HandlerError(vault::Error::InvalidKey)) => Err(Error::InvalidKey),
+            Err(SendError::HandlerError(vault::Error::LockedOut)) => Err(Error::LockedOut),
             Err(SendError::HandlerError(err)) => {
                 error!(?err, "Vault failed to unseal key");
                 Err(Error::InvalidKey)
@@ -191,17 +193,16 @@ impl VaultGate {
         let State::ReadyForExchange { secret, .. } = &self.state else {
             return Err(Error::State);
         };
-
+        let seal_key = Self::decrypt_key(secret, &nonce, &ciphertext, &associated_data)
-        let Ok(seal_key_buffer) = Self::decrypt_key(secret, &nonce, &ciphertext, &associated_data)
+            .map_err(|()| Error::InvalidKey)
-        else {
+            .and_then(Self::key_cell)?;
-            return Err(Error::InvalidKey);
-        };
 
         match self
             .actors
             .vault
             .ask(Bootstrap {
-                seal_key_raw: seal_key_buffer,
+                seal_key,
+                custody: None,
             })
             .await
         {
@@ -225,14 +226,53 @@ impl VaultGate {
 
     #[message]
     pub async fn handle_vault_state(&mut self) -> Result<VaultState, Error> {
-        let answer = self
+        self.actors
-            .actors
             .vault
             .ask(GetState {})
             .await
-            .map_err(|_| Error::internal("failed to query vault"))?;
+            .map_err(|_| Error::internal("failed to query vault"))
+    }
 
-        Ok(answer)
+    #[message]
+    pub async fn handle_declare_committee(&mut self, count: usize) -> Result<(), Error> {
+        self.actors
+            .vault_coordinator
+            .ask(StartBootstrap {
+                operator_id: self.auth_creds.id,
+                declared_count: count,
+            })
+            .await
+            .map_err(Error::ceremony)
+    }
+
+    #[message]
+    pub async fn handle_contribute_bootstrap_passphrase(
+        &mut self,
+        passphrase: Vec<u8>,
+    ) -> Result<bool, Error> {
+        self.actors
+            .vault_coordinator
+            .ask(ContributeBootstrap {
+                operator_id: self.auth_creds.id,
+                passphrase: SafeCell::new(passphrase),
+            })
+            .await
+            .map_err(Error::ceremony)
+    }
+
+    #[message]
+    pub async fn handle_contribute_unseal_passphrase(
+        &mut self,
+        passphrase: Vec<u8>,
+    ) -> Result<bool, Error> {
+        self.actors
+            .vault_coordinator
+            .ask(ContributeUnseal {
+                operator_id: self.auth_creds.id,
+                passphrase: SafeCell::new(passphrase),
+            })
+            .await
+            .map_err(Error::ceremony)
     }
 }
 
@@ -286,3 +326,75 @@ impl Message<events::Unsealed> for VaultGate {
         ctx.stop();
     }
 }
+
+pub enum Inbound {
+    HandleHandshake(HandleHandshake),
+    HandleUnsealEncryptedKey(HandleUnsealEncryptedKey),
+    HandleBootstrapEncryptedKey(HandleBootstrapEncryptedKey),
+    HandleVaultState,
+    HandleDeclareCommittee(HandleDeclareCommittee),
+    HandleContributeBootstrapPassphrase(HandleContributeBootstrapPassphrase),
+    HandleContributeUnsealPassphrase(HandleContributeUnsealPassphrase),
+}
+
+pub enum Outbound {
+    HandleHandshake(Result<HandshakeResponse, Error>),
+    HandleUnsealEncryptedKey(Result<(), Error>),
+    HandleBootstrapEncryptedKey(Result<(), Error>),
+    HandleVaultState(Result<VaultState, Error>),
+    HandleDeclareCommittee(Result<(), Error>),
+    HandleContributeBootstrapPassphrase(Result<bool, Error>),
+    HandleContributeUnsealPassphrase(Result<bool, Error>),
+}
+
+impl Message<Inbound> for VaultGate {
+    type Reply = Result<Outbound, Error>;
+
+    async fn handle(
+        &mut self,
+        msg: Inbound,
+        _ctx: &mut kameo::prelude::Context<Self, Self::Reply>,
+    ) -> Self::Reply {
+        match msg {
+            Inbound::HandleHandshake(message) => Ok(Outbound::HandleHandshake(
+                self.handle_handshake(message.client_pubkey),
+            )),
+            Inbound::HandleUnsealEncryptedKey(message) => Ok(Outbound::HandleUnsealEncryptedKey(
+                self.handle_unseal_encrypted_key(
+                    message.nonce,
+                    message.ciphertext,
+                    message.associated_data,
+                )
+                .await,
+            )),
+            Inbound::HandleBootstrapEncryptedKey(message) => {
+                Ok(Outbound::HandleBootstrapEncryptedKey(
+                    self.handle_bootstrap_encrypted_key(
+                        message.nonce,
+                        message.ciphertext,
+                        message.associated_data,
+                    )
+                    .await,
+                ))
+            }
+            Inbound::HandleVaultState => {
+                Ok(Outbound::HandleVaultState(self.handle_vault_state().await))
+            }
+            Inbound::HandleDeclareCommittee(message) => Ok(Outbound::HandleDeclareCommittee(
+                self.handle_declare_committee(message.count).await,
+            )),
+            Inbound::HandleContributeBootstrapPassphrase(message) => {
+                Ok(Outbound::HandleContributeBootstrapPassphrase(
+                    self.handle_contribute_bootstrap_passphrase(message.passphrase)
+                        .await,
+                ))
+            }
+            Inbound::HandleContributeUnsealPassphrase(message) => {
+                Ok(Outbound::HandleContributeUnsealPassphrase(
+                    self.handle_contribute_unseal_passphrase(message.passphrase)
+                        .await,
+                ))
+            }
+        }
+    }
+}

server/crates/arbiter-server/tests/client/auth.rs

@@ -1,15 +1,12 @@
 use super::common::ChannelTransport;
-use arbiter_crypto::{
+use arbiter_crypto::authn::{self, AuthChallenge, CLIENT_CONTEXT};
-    authn::{self, AuthChallenge, CLIENT_CONTEXT},
-    safecell::{SafeCell, SafeCellHandle as _},
-};
 use arbiter_proto::{
     ClientMetadata,
     transport::{Receiver, Sender},
 };
 use arbiter_server::{
     actors::{GlobalActors, vault::Bootstrap},
-    crypto::integrity,
+    crypto::{KeyCell, integrity},
     db::{self, schema},
     peers::client::{ClientConnection, ClientCredentials, auth, connect_client},
 };
@@ -100,7 +97,8 @@ async fn spawn_test_actors(db: &db::DatabasePool) -> GlobalActors {
     actors
         .vault
         .ask(Bootstrap {
-            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+            seal_key: KeyCell::from([0u8; 32]),
+            custody: None,
         })
         .await
         .unwrap();
@@ -266,7 +264,7 @@ pub async fn metadata_unchanged_does_not_append_history() {
 
 #[tokio::test]
 #[test_log::test]
-pub async fn metadata_change_appends_history_and_repoints_binding() {
+pub async fn metadata_frozen_after_approval_ignores_reconnect_changes() {
     let db = db::create_test_pool().await;
     let actors = spawn_test_actors(&db).await;
     let new_key = MlDsa87::key_gen(&mut rand::rng());
@@ -287,6 +285,7 @@ pub async fn metadata_change_appends_history_and_repoints_binding() {
         connect_client(props, &mut server_transport).await;
     });
 
+    // Reconnect presenting different metadata — must be silently ignored.
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
             pubkey: verifying_key(&new_key).into(),
@@ -313,6 +312,7 @@ pub async fn metadata_change_appends_history_and_repoints_binding() {
             client_metadata, client_metadata_history, program_client,
         };
         let mut conn = db.get().await.unwrap();
+        // Metadata is frozen: no new row, no history entry.
         let metadata_count: i64 = client_metadata::table
             .count()
             .get_result(&mut conn)
@@ -338,15 +338,19 @@ pub async fn metadata_change_appends_history_and_repoints_binding() {
             .first::<(String, Option<String>, Option<String>)>(&mut conn)
             .await
             .unwrap();
-        assert_eq!(metadata_count, 2);
+        assert_eq!(
-        assert_eq!(history_count, 1);
+            metadata_count, 1,
+            "frozen: no new metadata row on reconnect"
+        );
+        assert_eq!(history_count, 0, "frozen: no history entry on reconnect");
         assert_eq!(
             current,
             (
                 "client".to_owned(),
-                Some("new".to_owned()),
+                Some("old".to_owned()),
-                Some("2.0.0".to_owned())
+                Some("1.0.0".to_owned())
-            )
+            ),
+            "frozen: original metadata must be preserved"
         );
     }
 }

server/crates/arbiter-server/tests/common/mod.rs

@@ -2,10 +2,11 @@
     dead_code,
     reason = "Common test utilities that may not be used in every test"
 )]
-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+
 use arbiter_proto::transport::{Bi, Error, Receiver, Sender};
 use arbiter_server::{
     actors::{GlobalActors, vault::Vault},
+    crypto::KeyCell,
     db::{self, schema},
 };
 
@@ -19,7 +20,7 @@ pub(crate) async fn bootstrapped_vault(db: &db::DatabasePool) -> Vault {
         .await
         .unwrap();
     actor
-        .bootstrap(SafeCell::new(b"test-seal-key".to_vec()))
+        .bootstrap(KeyCell::from([0u8; 32]), None)
         .await
         .unwrap();
     actor

server/crates/arbiter-server/tests/operator/auth.rs

@@ -1,13 +1,10 @@
 use super::common::ChannelTransport;
-use arbiter_crypto::{
+use arbiter_crypto::authn::{self, AuthChallenge, OPERATOR_CONTEXT};
-    authn::{self, AuthChallenge, OPERATOR_CONTEXT},
-    safecell::{SafeCell, SafeCellHandle as _},
-};
 use arbiter_proto::transport::{Error as TransportError, Receiver, Sender};
 use arbiter_server::{
     actors::{GlobalActors, bootstrap::GetToken, vault::Bootstrap},
-    crypto::integrity,
+    crypto::{KeyCell, integrity},
-    db::{self, schema},
+    db::{self, models::OperatorId, schema},
     peers::operator::{self, Credentials, OperatorConnection, auth, vault_gate},
 };
 
@@ -154,13 +151,6 @@ impl Sender<auth::Inbound> for StartTestTransport {
 pub async fn bootstrap_token_auth() {
     let db = db::create_test_pool().await;
     let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-    actors
-        .vault
-        .ask(Bootstrap {
-            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
-        })
-        .await
-        .unwrap();
     let token = actors.bootstrapper.ask(GetToken).await.unwrap().unwrap();
 
     let (mut server_transport, mut test_transport) = ChannelTransport::new();
@@ -174,7 +164,7 @@ pub async fn bootstrap_token_auth() {
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
             pubkey: verifying_key(&new_key).into(),
-            bootstrap_token: Some(token),
+            bootstrap_token: Some(token.into_bytes()),
         })
         .await
         .unwrap();
@@ -231,7 +221,7 @@ pub async fn bootstrap_invalid_token_auth() {
     test_transport
         .send(auth::Inbound::AuthChallengeRequest {
             pubkey: verifying_key(&new_key).into(),
-            bootstrap_token: Some("invalid_token".to_owned()),
+            bootstrap_token: Some(b"invalid_token".to_vec()),
         })
         .await
         .unwrap();
@@ -275,7 +265,8 @@ pub async fn challenge_auth() {
     actors
         .vault
         .ask(Bootstrap {
-            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+            seal_key: KeyCell::from([0u8; 32]),
+            custody: None,
         })
         .await
         .unwrap();
@@ -285,10 +276,10 @@ pub async fn challenge_auth() {
 
     {
         let mut conn = db.get().await.unwrap();
-        let id: i32 = insert_into(schema::operator_identity::table)
+        let id: OperatorId = insert_into(schema::operator_identity::table)
             .values((schema::operator_identity::public_key.eq(pubkey_bytes.clone()),))
             .returning(schema::operator_identity::id)
-            .get_result(&mut conn)
+            .get_result::<OperatorId>(&mut conn)
             .await
             .unwrap();
         integrity::sign_entity(
@@ -361,7 +352,8 @@ pub async fn challenge_auth_rejects_integrity_tag_mismatch_when_unsealed() {
     actors
         .vault
         .ask(Bootstrap {
-            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+            seal_key: KeyCell::from([0u8; 32]),
+            custody: None,
         })
         .await
         .unwrap();
@@ -400,7 +392,7 @@ pub async fn challenge_auth_rejects_integrity_tag_mismatch_when_unsealed() {
     let challenge = match response {
         Ok(resp) => match resp {
             auth::Outbound::AuthChallenge { challenge } => challenge,
-            other => panic!("Expected AuthChallenge, got {other:?}"),
+            other @ auth::Outbound::AuthSuccess => panic!("Expected AuthChallenge, got {other:?}"),
         },
         Err(err) => panic!("Expected Ok response, got Err({err:?})"),
     };
@@ -434,7 +426,8 @@ pub async fn challenge_auth_rejects_invalid_signature() {
     actors
         .vault
         .ask(Bootstrap {
-            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+            seal_key: KeyCell::from([0u8; 32]),
+            custody: None,
         })
         .await
         .unwrap();
@@ -444,10 +437,10 @@ pub async fn challenge_auth_rejects_invalid_signature() {
 
     {
         let mut conn = db.get().await.unwrap();
-        let id: i32 = insert_into(schema::operator_identity::table)
+        let id: OperatorId = insert_into(schema::operator_identity::table)
             .values((schema::operator_identity::public_key.eq(pubkey_bytes.clone()),))
             .returning(schema::operator_identity::id)
-            .get_result(&mut conn)
+            .get_result::<OperatorId>(&mut conn)
             .await
             .unwrap();
         integrity::sign_entity(
@@ -506,3 +499,92 @@ pub async fn challenge_auth_rejects_invalid_signature() {
         Err(auth::Error::InvalidChallengeSolution)
     ));
 }
+
+/// The bootstrap token authorises registering committee members *before* the
+/// vault exists. Once any bootstrap path succeeds it must stop working, or its
+/// holder could keep minting operator identities until the next restart.
+#[tokio::test]
+#[test_log::test]
+pub async fn bootstrap_token_rejected_after_bootstrap() {
+    let db = db::create_test_pool().await;
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let token = actors.bootstrapper.ask(GetToken).await.unwrap().unwrap();
+
+    actors
+        .vault
+        .ask(Bootstrap {
+            seal_key: KeyCell::from([0u8; 32]),
+            custody: None,
+        })
+        .await
+        .unwrap();
+
+    // `Bootstrapped` travels through the message bus, so the token disappears
+    // a couple of actor turns after the bootstrap call returns.
+    let mut retired = false;
+    for _ in 0..100 {
+        if actors.bootstrapper.ask(GetToken).await.unwrap().is_none() {
+            retired = true;
+            break;
+        }
+        tokio::task::yield_now().await;
+    }
+    assert!(
+        retired,
+        "the bootstrap token must be retired once the vault is bootstrapped"
+    );
+
+    let (mut server_transport, mut test_transport) = ChannelTransport::new();
+    let db_for_task = db.clone();
+    let task = tokio::spawn(async move {
+        let mut props = OperatorConnection::new(db_for_task, actors);
+        auth::authenticate(&mut props, &mut server_transport).await
+    });
+
+    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    test_transport
+        .send(auth::Inbound::AuthChallengeRequest {
+            pubkey: verifying_key(&new_key).into(),
+            bootstrap_token: Some(token.into_bytes()),
+        })
+        .await
+        .unwrap();
+
+    let response = test_transport
+        .recv()
+        .await
+        .expect("should receive challenge");
+    let challenge = match response {
+        Ok(auth::Outbound::AuthChallenge { challenge }) => challenge,
+        other => panic!("Expected AuthChallenge, got {other:?}"),
+    };
+
+    let signature = sign_operator_challenge(&new_key, &challenge);
+    test_transport
+        .send(auth::Inbound::AuthChallengeSolution {
+            signature: signature.to_bytes(),
+        })
+        .await
+        .unwrap();
+
+    let response = test_transport
+        .recv()
+        .await
+        .expect("should receive auth result");
+    assert!(
+        matches!(response, Err(auth::Error::InvalidBootstrapToken)),
+        "a spent bootstrap token must not authorise a new identity, got {response:?}"
+    );
+    assert!(task.await.unwrap().is_err(), "authentication must fail");
+
+    let mut conn = db.get().await.unwrap();
+    let registered: i64 = schema::operator_identity::table
+        .count()
+        .get_result(&mut conn)
+        .await
+        .unwrap();
+    assert_eq!(
+        registered, 0,
+        "no identity may be registered after the bootstrap"
+    );
+}

server/crates/arbiter-server/tests/operator/unseal.rs

@@ -1,13 +1,11 @@
-use arbiter_crypto::{
+use arbiter_crypto::authn;
-    authn,
-    safecell::{SafeCell, SafeCellHandle as _},
-};
 use arbiter_server::{
     actors::{
         GlobalActors,
         vault::{Bootstrap, Seal},
     },
-    db,
+    crypto::KeyCell,
+    db::{self, models::OperatorId},
     peers::operator::{
         Credentials,
         vault_gate::{
@@ -22,7 +20,7 @@ use tokio::sync::oneshot;
 use x25519_dalek::{EphemeralSecret, PublicKey};
 
 async fn setup_sealed_gate(
-    seal_key: &[u8],
+    seal_key: [u8; 32],
 ) -> (
     db::DatabasePool,
     kameo::actor::ActorRef<VaultGate>,
@@ -34,7 +32,8 @@ async fn setup_sealed_gate(
     actors
         .vault
         .ask(Bootstrap {
-            seal_key_raw: SafeCell::new(seal_key.to_vec()),
+            seal_key: KeyCell::from(seal_key),
+            custody: None,
         })
         .await
         .unwrap();
@@ -42,7 +41,10 @@ async fn setup_sealed_gate(
 
     let (promotion_tx, promotion_rx) = oneshot::channel();
     let pubkey = authn::SigningKey::generate().public_key();
-    let auth_creds = Credentials { id: 1, pubkey };
+    let auth_creds = Credentials {
+        id: OperatorId::from_raw(1),
+        pubkey,
+    };
     let gate = VaultGate::spawn(VaultGate::new(auth_creds, actors, db.clone(), promotion_tx));
 
     (db, gate, promotion_rx)
@@ -83,10 +85,10 @@ async fn client_dh_encrypt(
 #[tokio::test]
 #[test_log::test]
 pub async fn unseal_success() {
-    let seal_key = b"test-seal-key";
+    let seal_key = [7u8; 32];
     let (_db, gate, _promotion_rx) = setup_sealed_gate(seal_key).await;
 
-    let encrypted_key = client_dh_encrypt(&gate, seal_key).await;
+    let encrypted_key = client_dh_encrypt(&gate, &seal_key).await;
 
     let response = gate.ask(encrypted_key).await;
     assert!(matches!(response, Ok(())));
@@ -95,10 +97,10 @@ pub async fn unseal_success() {
 #[tokio::test]
 #[test_log::test]
 pub async fn unseal_wrong_seal_key() {
-    let seal_key = b"test-seal-key";
+    let seal_key = [7u8; 32];
     let (_db, gate, _promotion_rx) = setup_sealed_gate(seal_key).await;
 
-    let encrypted_key = client_dh_encrypt(&gate, b"wrong-key").await;
+    let encrypted_key = client_dh_encrypt(&gate, &[8u8; 32]).await;
 
     let response = gate.ask(encrypted_key).await;
     assert!(matches!(
@@ -112,7 +114,7 @@ pub async fn unseal_wrong_seal_key() {
 #[tokio::test]
 #[test_log::test]
 pub async fn unseal_corrupted_ciphertext() {
-    let seal_key = b"test-seal-key";
+    let seal_key = [7u8; 32];
     let (_db, gate, _promotion_rx) = setup_sealed_gate(seal_key).await;
 
     let client_secret = EphemeralSecret::random();
@@ -143,11 +145,11 @@ pub async fn unseal_corrupted_ciphertext() {
 #[tokio::test]
 #[test_log::test]
 pub async fn unseal_retry_after_invalid_key() {
-    let seal_key = b"real-seal-key";
+    let seal_key = [9u8; 32];
     let (_db, gate, _promotion_rx) = setup_sealed_gate(seal_key).await;
 
     {
-        let encrypted_key = client_dh_encrypt(&gate, b"wrong-key").await;
+        let encrypted_key = client_dh_encrypt(&gate, &[8u8; 32]).await;
 
         let response = gate.ask(encrypted_key).await;
         assert!(matches!(
@@ -159,7 +161,7 @@ pub async fn unseal_retry_after_invalid_key() {
     }
 
     {
-        let encrypted_key = client_dh_encrypt(&gate, seal_key).await;
+        let encrypted_key = client_dh_encrypt(&gate, &seal_key).await;
 
         let response = gate.ask(encrypted_key).await;
         assert!(matches!(response, Ok(())));

server/crates/arbiter-server/tests/vault.rs

@@ -2,6 +2,8 @@ mod common;
 
 #[path = "vault/concurrency.rs"]
 mod concurrency;
+#[path = "vault/custody.rs"]
+mod custody;
 #[path = "vault/lifecycle.rs"]
 mod lifecycle;
 #[path = "vault/storage.rs"]

server/crates/arbiter-server/tests/vault/concurrency.rs

@@ -5,6 +5,7 @@ use arbiter_server::{
         GlobalActors,
         vault::{CreateNew, Error, Vault},
     },
+    crypto::KeyCell,
     db::{self, models, schema},
 };
 
@@ -14,6 +15,8 @@ use kameo::actor::{ActorRef, Spawn as _};
 use std::collections::{HashMap, HashSet};
 use tokio::task::JoinSet;
 
+const TEST_AAD: &[u8] = b"test-aad";
+
 async fn write_concurrently(
     actor: ActorRef<Vault>,
     prefix: &'static str,
@@ -27,6 +30,7 @@ async fn write_concurrently(
             let id = actor
                 .ask(CreateNew {
                     plaintext: SafeCell::new(plaintext.clone()),
+                    aad: TEST_AAD.to_vec(),
                 })
                 .await
                 .unwrap();
@@ -120,7 +124,7 @@ async fn insert_failure_does_not_create_partial_row() {
     drop(conn);
 
     let err = actor
-        .create_new(SafeCell::new(b"should fail".to_vec()))
+        .create_new(SafeCell::new(b"should fail".to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap_err();
     assert!(matches!(err, Error::DatabaseTransaction(_)));
@@ -166,12 +170,12 @@ async fn decrypt_roundtrip_after_high_concurrency() {
         .await
         .unwrap();
     decryptor
-        .try_unseal(SafeCell::new(b"test-seal-key".to_vec()))
+        .try_unseal(KeyCell::from([0u8; 32]))
         .await
         .unwrap();
 
     for (id, plaintext) in expected {
-        let mut decrypted = decryptor.decrypt(id).await.unwrap();
+        let mut decrypted = decryptor.decrypt(id, TEST_AAD.to_vec()).await.unwrap();
         assert_eq!(*decrypted.read(), plaintext);
     }
 }

server/crates/arbiter-server/tests/vault/custody.rs

@@ -0,0 +1,317 @@
+//! End-to-end coverage for the Shamir custody ceremonies.
+
+use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+use arbiter_server::{
+    actors::{
+        GlobalActors,
+        vault::{Bootstrap, GetState, Seal, VaultState},
+        vault_coordinator::{ContributeBootstrap, ContributeUnseal, StartBootstrap},
+    },
+    crypto::{KeyCell, shamir},
+    db::{self, models::OperatorId, schema},
+};
+
+use diesel::{ExpressionMethods as _, QueryDsl};
+use diesel_async::RunQueryDsl;
+
+/// Register `count` operator identities so committee members satisfy the
+/// foreign key from `operator` to `operator_identity`.
+async fn register_operators(db: &db::DatabasePool, count: usize) -> Vec<OperatorId> {
+    let mut conn = db.get().await.unwrap();
+    let mut ids = Vec::with_capacity(count);
+    for index in 0..count {
+        let pubkey = vec![u8::try_from(index).unwrap(); 32];
+        let id: OperatorId = diesel::insert_into(schema::operator_identity::table)
+            .values((schema::operator_identity::public_key.eq(pubkey),))
+            .returning(schema::operator_identity::id)
+            .get_result(&mut conn)
+            .await
+            .unwrap();
+        ids.push(id);
+    }
+    ids
+}
+
+async fn stored_share_count(db: &db::DatabasePool) -> i64 {
+    let mut conn = db.get().await.unwrap();
+    schema::operator::table
+        .count()
+        .get_result(&mut conn)
+        .await
+        .unwrap()
+}
+
+async fn stored_threshold(db: &db::DatabasePool) -> Option<i32> {
+    let mut conn = db.get().await.unwrap();
+    schema::arbiter_settings::table
+        .select(schema::arbiter_settings::shamir_threshold)
+        .first(&mut conn)
+        .await
+        .unwrap()
+}
+
+fn passphrase(seed: u8) -> SafeCell<Vec<u8>> {
+    SafeCell::new(vec![seed; 16])
+}
+
+/// The happy path: three operators bootstrap, and any two of them reopen the
+/// vault after it is sealed.
+#[tokio::test]
+#[test_log::test]
+async fn committee_of_three_unseals_with_two_passphrases() {
+    let db = db::create_test_pool().await;
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let operators = register_operators(&db, 3).await;
+
+    actors
+        .vault_coordinator
+        .ask(StartBootstrap {
+            operator_id: operators[0],
+            declared_count: 3,
+        })
+        .await
+        .unwrap();
+
+    for (index, operator_id) in operators.iter().enumerate() {
+        let finished = actors
+            .vault_coordinator
+            .ask(ContributeBootstrap {
+                operator_id: *operator_id,
+                passphrase: passphrase(u8::try_from(index).unwrap()),
+            })
+            .await
+            .unwrap();
+        assert_eq!(
+            finished,
+            index == 2,
+            "the ceremony finishes only on the last contribution"
+        );
+    }
+
+    assert_eq!(
+        actors.vault.ask(GetState {}).await.unwrap(),
+        VaultState::Unsealed
+    );
+    assert_eq!(stored_share_count(&db).await, 3);
+    assert_eq!(stored_threshold(&db).await, Some(2));
+
+    actors.vault.ask(Seal {}).await.unwrap();
+
+    let first = actors
+        .vault_coordinator
+        .ask(ContributeUnseal {
+            operator_id: operators[0],
+            passphrase: passphrase(0),
+        })
+        .await
+        .unwrap();
+    assert!(!first, "one of two shares must not unseal");
+
+    let second = actors
+        .vault_coordinator
+        .ask(ContributeUnseal {
+            operator_id: operators[2],
+            passphrase: passphrase(2),
+        })
+        .await
+        .unwrap();
+    assert!(second, "the threshold contribution should unseal the vault");
+    assert_eq!(
+        actors.vault.ask(GetState {}).await.unwrap(),
+        VaultState::Unsealed
+    );
+}
+
+/// Shares that describe a seal key the vault never adopted would make the vault
+/// permanently un-unsealable, so a refused bootstrap must leave the table empty.
+#[tokio::test]
+#[test_log::test]
+async fn refused_bootstrap_stores_no_shares() {
+    let db = db::create_test_pool().await;
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let operators = register_operators(&db, 1).await;
+
+    // Another path bootstraps the vault first; the ceremony now has nowhere to go.
+    actors
+        .vault
+        .ask(Bootstrap {
+            seal_key: KeyCell::from([4u8; 32]),
+            custody: None,
+        })
+        .await
+        .unwrap();
+
+    actors
+        .vault_coordinator
+        .ask(StartBootstrap {
+            operator_id: operators[0],
+            declared_count: 1,
+        })
+        .await
+        .unwrap();
+
+    let error = actors
+        .vault_coordinator
+        .ask(ContributeBootstrap {
+            operator_id: operators[0],
+            passphrase: passphrase(1),
+        })
+        .await
+        .expect_err("bootstrapping an already bootstrapped vault must fail");
+    assert!(
+        format!("{error:?}").contains("AlreadyBootstrapped"),
+        "expected AlreadyBootstrapped, got {error:?}"
+    );
+
+    assert_eq!(
+        stored_share_count(&db).await,
+        0,
+        "a refused bootstrap must not leave shares behind"
+    );
+    assert_eq!(
+        stored_threshold(&db).await,
+        None,
+        "a refused bootstrap must not leave a threshold behind"
+    );
+}
+
+#[tokio::test]
+#[test_log::test]
+async fn oversized_and_degenerate_committees_are_rejected() {
+    let db = db::create_test_pool().await;
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let operators = register_operators(&db, 1).await;
+
+    for (count, expected) in [
+        (0_usize, "EmptyCommittee"),
+        (2, "UnsupportedCommittee"),
+        (shamir::MAX_COMMITTEE_SIZE + 1, "CommitteeTooLarge"),
+        (usize::MAX, "CommitteeTooLarge"),
+    ] {
+        let error = actors
+            .vault_coordinator
+            .ask(StartBootstrap {
+                operator_id: operators[0],
+                declared_count: count,
+            })
+            .await
+            .expect_err("committee size must be rejected");
+        assert!(
+            format!("{error:?}").contains(expected),
+            "expected {expected} for count {count}, got {error:?}"
+        );
+    }
+}
+
+/// A committee whose members never all show up would otherwise wedge the
+/// coordinator until restart. Only the operator that declared it may reset it.
+#[tokio::test]
+#[test_log::test]
+async fn only_the_declarer_may_restart_a_stalled_committee() {
+    let db = db::create_test_pool().await;
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let operators = register_operators(&db, 3).await;
+
+    actors
+        .vault_coordinator
+        .ask(StartBootstrap {
+            operator_id: operators[0],
+            declared_count: 3,
+        })
+        .await
+        .unwrap();
+    actors
+        .vault_coordinator
+        .ask(ContributeBootstrap {
+            operator_id: operators[0],
+            passphrase: passphrase(0),
+        })
+        .await
+        .unwrap();
+
+    let error = actors
+        .vault_coordinator
+        .ask(StartBootstrap {
+            operator_id: operators[1],
+            declared_count: 3,
+        })
+        .await
+        .expect_err("a bystander must not reset someone else's ceremony");
+    assert!(
+        format!("{error:?}").contains("AlreadyBootstrapping"),
+        "expected AlreadyBootstrapping, got {error:?}"
+    );
+
+    actors
+        .vault_coordinator
+        .ask(StartBootstrap {
+            operator_id: operators[0],
+            declared_count: 1,
+        })
+        .await
+        .expect("the declarer may restart the ceremony");
+
+    let finished = actors
+        .vault_coordinator
+        .ask(ContributeBootstrap {
+            operator_id: operators[0],
+            passphrase: passphrase(0),
+        })
+        .await
+        .unwrap();
+    assert!(
+        finished,
+        "the restarted one-operator ceremony should complete"
+    );
+    assert_eq!(stored_share_count(&db).await, 1);
+}
+
+/// A wrong passphrase must not unseal, and the operator must be able to retry.
+#[tokio::test]
+#[test_log::test]
+async fn wrong_passphrase_is_rejected_and_retryable() {
+    let db = db::create_test_pool().await;
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let operators = register_operators(&db, 1).await;
+
+    actors
+        .vault_coordinator
+        .ask(StartBootstrap {
+            operator_id: operators[0],
+            declared_count: 1,
+        })
+        .await
+        .unwrap();
+    actors
+        .vault_coordinator
+        .ask(ContributeBootstrap {
+            operator_id: operators[0],
+            passphrase: passphrase(7),
+        })
+        .await
+        .unwrap();
+    actors.vault.ask(Seal {}).await.unwrap();
+
+    let error = actors
+        .vault_coordinator
+        .ask(ContributeUnseal {
+            operator_id: operators[0],
+            passphrase: passphrase(8),
+        })
+        .await
+        .expect_err("a wrong passphrase must not unseal");
+    assert!(
+        format!("{error:?}").contains("InvalidPassphrase"),
+        "expected InvalidPassphrase, got {error:?}"
+    );
+
+    let unsealed = actors
+        .vault_coordinator
+        .ask(ContributeUnseal {
+            operator_id: operators[0],
+            passphrase: passphrase(7),
+        })
+        .await
+        .expect("the operator may retry with the correct passphrase");
+    assert!(unsealed, "the retry should unseal the vault");
+}

server/crates/arbiter-server/tests/vault/lifecycle.rs

@@ -5,23 +5,28 @@ use arbiter_server::{
         GlobalActors,
         vault::{Error, Vault},
     },
-    crypto::encryption::v1::{Nonce, ROOT_KEY_TAG},
+    crypto::{
+        KeyCell,
+        encryption::v1::{Nonce, ROOT_KEY_TAG},
+    },
     db::{self, models, schema},
 };
 
 use diesel::{QueryDsl, SelectableHelper};
 use diesel_async::RunQueryDsl;
 
+const TEST_AAD: &[u8] = b"test-aad";
+
 #[tokio::test]
 #[test_log::test]
-async fn test_bootstrap() {
+async fn bootstrap() {
     let db = db::create_test_pool().await;
     let mut actor = Vault::new(db.clone(), GlobalActors::spawn_message_bus())
         .await
         .unwrap();
 
-    let seal_key = SafeCell::new(b"test-seal-key".to_vec());
+    let seal_key = KeyCell::from([0u8; 32]);
-    actor.bootstrap(seal_key).await.unwrap();
+    actor.bootstrap(seal_key, None).await.unwrap();
 
     let mut conn = db.get().await.unwrap();
     let row: models::RootKeyHistory = schema::root_key_history::table
@@ -39,25 +44,25 @@ async fn test_bootstrap() {
 
 #[tokio::test]
 #[test_log::test]
-async fn test_bootstrap_rejects_double() {
+async fn bootstrap_rejects_double() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_vault(&db).await;
 
-    let seal_key2 = SafeCell::new(b"test-seal-key".to_vec());
+    let seal_key2 = KeyCell::from([0u8; 32]);
-    let err = actor.bootstrap(seal_key2).await.unwrap_err();
+    let err = actor.bootstrap(seal_key2, None).await.unwrap_err();
     assert!(matches!(err, Error::AlreadyBootstrapped));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_create_new_before_bootstrap_fails() {
+async fn create_new_before_bootstrap_fails() {
     let db = db::create_test_pool().await;
     let mut actor = Vault::new(db, GlobalActors::spawn_message_bus())
         .await
         .unwrap();
 
     let err = actor
-        .create_new(SafeCell::new(b"data".to_vec()))
+        .create_new(SafeCell::new(b"data".to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap_err();
     assert!(matches!(err, Error::NotBootstrapped));
@@ -65,19 +70,19 @@ async fn test_create_new_before_bootstrap_fails() {
 
 #[tokio::test]
 #[test_log::test]
-async fn test_decrypt_before_bootstrap_fails() {
+async fn decrypt_before_bootstrap_fails() {
     let db = db::create_test_pool().await;
     let mut actor = Vault::new(db, GlobalActors::spawn_message_bus())
         .await
         .unwrap();
 
-    let err = actor.decrypt(1).await.unwrap_err();
+    let err = actor.decrypt(1, TEST_AAD.to_vec()).await.unwrap_err();
     assert!(matches!(err, Error::NotBootstrapped));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_new_restores_sealed_state() {
+async fn new_restores_sealed_state() {
     let db = db::create_test_pool().await;
     let actor = common::bootstrapped_vault(&db).await;
     drop(actor);
@@ -85,19 +90,19 @@ async fn test_new_restores_sealed_state() {
     let mut actor2 = Vault::new(db, GlobalActors::spawn_message_bus())
         .await
         .unwrap();
-    let err = actor2.decrypt(1).await.unwrap_err();
+    let err = actor2.decrypt(1, TEST_AAD.to_vec()).await.unwrap_err();
     assert!(matches!(err, Error::Sealed));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_unseal_correct_password() {
+async fn unseal_correct_password() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_vault(&db).await;
 
     let plaintext = b"survive a restart";
     let aead_id = actor
-        .create_new(SafeCell::new(plaintext.to_vec()))
+        .create_new(SafeCell::new(plaintext.to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap();
     drop(actor);
@@ -105,22 +110,22 @@ async fn test_unseal_correct_password() {
     let mut actor = Vault::new(db.clone(), GlobalActors::spawn_message_bus())
         .await
         .unwrap();
-    let seal_key = SafeCell::new(b"test-seal-key".to_vec());
+    let seal_key = KeyCell::from([0u8; 32]);
     actor.try_unseal(seal_key).await.unwrap();
 
-    let mut decrypted = actor.decrypt(aead_id).await.unwrap();
+    let mut decrypted = actor.decrypt(aead_id, TEST_AAD.to_vec()).await.unwrap();
     assert_eq!(*decrypted.read(), plaintext);
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_unseal_wrong_then_correct_password() {
+async fn unseal_wrong_then_correct_password() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_vault(&db).await;
 
     let plaintext = b"important data";
     let aead_id = actor
-        .create_new(SafeCell::new(plaintext.to_vec()))
+        .create_new(SafeCell::new(plaintext.to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap();
     drop(actor);
@@ -129,13 +134,13 @@ async fn test_unseal_wrong_then_correct_password() {
         .await
         .unwrap();
 
-    let bad_key = SafeCell::new(b"wrong-password".to_vec());
+    let bad_key = KeyCell::from([1u8; 32]);
     let err = actor.try_unseal(bad_key).await.unwrap_err();
     assert!(matches!(err, Error::InvalidKey));
 
-    let good_key = SafeCell::new(b"test-seal-key".to_vec());
+    let good_key = KeyCell::from([0u8; 32]);
     actor.try_unseal(good_key).await.unwrap();
 
-    let mut decrypted = actor.decrypt(aead_id).await.unwrap();
+    let mut decrypted = actor.decrypt(aead_id, TEST_AAD.to_vec()).await.unwrap();
     assert_eq!(*decrypted.read(), plaintext);
 }

server/crates/arbiter-server/tests/vault/storage.rs

@@ -10,45 +10,47 @@ use diesel::{ExpressionMethods as _, QueryDsl, SelectableHelper, dsl::update};
 use diesel_async::RunQueryDsl;
 use std::collections::HashSet;
 
+const TEST_AAD: &[u8] = b"test-aad";
+
 #[tokio::test]
 #[test_log::test]
-async fn test_create_decrypt_roundtrip() {
+async fn create_decrypt_roundtrip() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_vault(&db).await;
 
     let plaintext = b"hello arbiter";
     let aead_id = actor
-        .create_new(SafeCell::new(plaintext.to_vec()))
+        .create_new(SafeCell::new(plaintext.to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap();
 
-    let mut decrypted = actor.decrypt(aead_id).await.unwrap();
+    let mut decrypted = actor.decrypt(aead_id, TEST_AAD.to_vec()).await.unwrap();
     assert_eq!(*decrypted.read(), plaintext);
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_decrypt_nonexistent_returns_not_found() {
+async fn decrypt_nonexistent_returns_not_found() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_vault(&db).await;
 
-    let err = actor.decrypt(9999).await.unwrap_err();
+    let err = actor.decrypt(9999, TEST_AAD.to_vec()).await.unwrap_err();
     assert!(matches!(err, Error::NotFound));
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_ciphertext_differs_across_entries() {
+async fn ciphertext_differs_across_entries() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_vault(&db).await;
 
     let plaintext = b"same content";
     let id1 = actor
-        .create_new(SafeCell::new(plaintext.to_vec()))
+        .create_new(SafeCell::new(plaintext.to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap();
     let id2 = actor
-        .create_new(SafeCell::new(plaintext.to_vec()))
+        .create_new(SafeCell::new(plaintext.to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap();
 
@@ -68,22 +70,22 @@ async fn test_ciphertext_differs_across_entries() {
 
     assert_ne!(row1.ciphertext, row2.ciphertext);
 
-    let mut d1 = actor.decrypt(id1).await.unwrap();
+    let mut d1 = actor.decrypt(id1, TEST_AAD.to_vec()).await.unwrap();
-    let mut d2 = actor.decrypt(id2).await.unwrap();
+    let mut d2 = actor.decrypt(id2, TEST_AAD.to_vec()).await.unwrap();
     assert_eq!(*d1.read(), plaintext);
     assert_eq!(*d2.read(), plaintext);
 }
 
 #[tokio::test]
 #[test_log::test]
-async fn test_nonce_never_reused() {
+async fn nonce_never_reused() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_vault(&db).await;
 
     let n = 5;
     for i in 0..n {
         actor
-            .create_new(SafeCell::new(format!("secret {i}").into_bytes()))
+            .create_new(SafeCell::new(format!("secret {i}").into_bytes()), TEST_AAD.to_vec())
             .await
             .unwrap();
     }
@@ -137,7 +139,7 @@ async fn broken_db_nonce_format_fails_closed() {
     drop(conn);
 
     let err = actor
-        .create_new(SafeCell::new(b"must fail".to_vec()))
+        .create_new(SafeCell::new(b"must fail".to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap_err();
     assert!(matches!(err, Error::BrokenDatabase));
@@ -145,7 +147,7 @@ async fn broken_db_nonce_format_fails_closed() {
     let db = db::create_test_pool().await;
     let mut actor = common::bootstrapped_vault(&db).await;
     let id = actor
-        .create_new(SafeCell::new(b"decrypt target".to_vec()))
+        .create_new(SafeCell::new(b"decrypt target".to_vec()), TEST_AAD.to_vec())
         .await
         .unwrap();
     let mut conn = db.get().await.unwrap();
@@ -156,6 +158,6 @@ async fn broken_db_nonce_format_fails_closed() {
         .unwrap();
     drop(conn);
 
-    let err = actor.decrypt(id).await.unwrap_err();
+    let err = actor.decrypt(id, TEST_AAD.to_vec()).await.unwrap_err();
     assert!(matches!(err, Error::BrokenDatabase));
 }