feat(server): unify integrity API and propagate verified IDs through auth/EVM flows

2026-04-07 21:12:36 +02:00
57 changed files with 1188 additions and 1015 deletions
--- a/IMPLEMENTATION.md
+++ b/IMPLEMENTATION.md
@@ -67,14 +67,18 @@ The `program_client.nonce` column stores the **next usable nonce** — i.e. it i
 ## Cryptography

 ### Authentication
- **Client protocol:** ML-DSA
+- **Client protocol:** ed25519

 ### User-Agent Authentication

 User-agent authentication supports multiple signature schemes because platform-provided "hardware-bound" keys do not expose a uniform algorithm across operating systems and hardware.

- **Supported schemes:** ML-DSA
- **Why:** Secure Enclave (MacOS) support them natively, on other platforms we could emulate while they roll-out
+- **Supported schemes:** RSA, Ed25519, ECDSA (secp256k1)
+- **Why:** the user agent authenticates with keys backed by platform facilities, and those facilities differ by platform
+- **Apple Silicon Secure Enclave / Secure Element:** ECDSA-only in practice
+- **Windows Hello / TPM 2.0:** currently RSA-backed in our integration
+
+This is why the user-agent auth protocol carries an explicit `KeyType`, while the SDK client protocol remains fixed to ed25519.

 ### Encryption at Rest
 - **Scheme:** Symmetric AEAD — currently **XChaCha20-Poly1305**
--- a/server/Cargo.lock
+++ b/server/Cargo.lock
@@ -347,7 +347,7 @@ dependencies = [
 "ruint",
 "rustc-hash",
 "serde",
- "sha3 0.10.8",
+ "sha3",
 ]

 [[package]]
@@ -548,7 +548,7 @@ dependencies = [
 "proc-macro-error2",
 "proc-macro2",
 "quote",
- "sha3 0.10.8",
+ "sha3",
 "syn 2.0.117",
 "syn-solidity",
 ]
@@ -680,9 +680,9 @@ name = "arbiter-client"
 version = "0.1.0"
 dependencies = [
 "alloy",
- "arbiter-crypto",
 "arbiter-proto",
 "async-trait",
+ "ed25519-dalek",
 "http",
 "rand 0.10.0",
 "rustls-webpki",
@@ -692,29 +692,6 @@ dependencies = [
 "tonic",
 ]

-[[package]]
-name = "arbiter-crypto"
-version = "0.1.0"
-dependencies = [
- "alloy",
- "base64",
- "chrono",
- "hmac",
- "memsafe",
- "ml-dsa",
- "rand 0.10.0",
-]
-
-[[package]]
-name = "arbiter-macros"
-version = "0.1.0"
-dependencies = [
- "arbiter-crypto",
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "arbiter-proto"
 version = "0.1.0"
@@ -748,8 +725,6 @@ version = "0.1.0"
 dependencies = [
 "alloy",
 "anyhow",
- "arbiter-crypto",
- "arbiter-macros",
 "arbiter-proto",
 "arbiter-tokens-registry",
 "argon2",
@@ -767,7 +742,7 @@ dependencies = [
 "insta",
 "k256",
 "kameo",
- "ml-dsa",
+ "memsafe",
 "mutants",
 "pem",
 "proptest",
@@ -776,13 +751,14 @@ dependencies = [
 "rand 0.10.0",
 "rcgen",
 "restructed",
+ "rsa",
 "rstest",
 "rustls",
 "secrecy",
 "serde_with",
 "sha2 0.10.9",
 "smlang",
- "spki 0.7.3",
+ "spki",
 "strum 0.28.0",
 "subtle",
 "test-log",
@@ -1473,12 +1449,6 @@ dependencies = [
 "cc",
 ]

-[[package]]
-name = "cmov"
-version = "0.5.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f88a43d011fc4a6876cb7344703e297c71dda42494fee094d5f7c76bf13f746"
-
 [[package]]
 name = "console"
 version = "0.15.11"
@@ -1509,12 +1479,6 @@ version = "0.9.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2459377285ad874054d797f3ccebf984978aa39129f6eafde5cdc8315b612f8"

-[[package]]
-name = "const-oid"
-version = "0.10.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a6ef517f0926dd24a1582492c791b6a4818a4d94e789a334894aa15b0d12f55c"
-
 [[package]]
 name = "const_format"
 version = "0.2.35"
@@ -1636,15 +1600,6 @@ dependencies = [
 "hybrid-array",
 ]

-[[package]]
-name = "ctutils"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d5515a3834141de9eafb9717ad39eea8247b5674e6066c404e8c4b365d2a29e"
-dependencies = [
- "cmov",
-]
-
 [[package]]
 name = "curve25519-dalek"
 version = "4.1.3"
@@ -1783,17 +1738,8 @@ version = "0.7.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e7c1832837b905bbfb5101e07cc24c8deddf52f93225eee6ead5f4d63d53ddcb"
 dependencies = [
- "const-oid 0.9.6",
- "zeroize",
-]
-
-[[package]]
-name = "der"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "71fd89660b2dc699704064e59e9dba0147b903e85319429e131620d022be411b"
-dependencies = [
- "const-oid 0.10.2",
+ "const-oid",
+ "pem-rfc7468",
 "zeroize",
 ]

@@ -1936,7 +1882,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
 "block-buffer 0.10.4",
- "const-oid 0.9.6",
+ "const-oid",
 "crypto-common 0.1.7",
 "subtle",
 ]
@@ -2000,13 +1946,13 @@ version = "0.16.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ee27f32b5c5292967d2d4a9d7f1e0b0aed2c15daded5a60300e4abb9d8020bca"
 dependencies = [
- "der 0.7.10",
+ "der",
 "digest 0.10.7",
 "elliptic-curve",
 "rfc6979",
 "serdect",
 "signature 2.2.0",
- "spki 0.7.3",
+ "spki",
 ]

 [[package]]
@@ -2015,6 +1961,7 @@ version = "3.0.0-rc.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c6e914c7c52decb085cea910552e24c63ac019e3ab8bf001ff736da9a9d9d890"
 dependencies = [
+ "serde",
 "signature 3.0.0-rc.10",
 ]

@@ -2027,6 +1974,7 @@ dependencies = [
 "curve25519-dalek 5.0.0-pre.6",
 "ed25519",
 "rand_core 0.10.0",
+ "serde",
 "sha2 0.11.0-rc.5",
 "subtle",
 "zeroize",
@@ -2065,7 +2013,7 @@ dependencies = [
 "ff",
 "generic-array",
 "group",
- "pkcs8 0.10.2",
+ "pkcs8",
 "rand_core 0.6.4",
 "sec1",
 "serdect",
@@ -2612,7 +2560,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8655f91cd07f2b9d0c24137bd650fe69617773435ee5ec83022377777ce65ef1"
 dependencies = [
 "typenum",
- "zeroize",
 ]

 [[package]]
@@ -3010,16 +2957,6 @@ dependencies = [
 "cpufeatures 0.2.17",
 ]

-[[package]]
-name = "keccak"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9e24a010dd405bd7ed803e5253182815b41bf2e6a80cc3bfc066658e03a198aa"
-dependencies = [
- "cfg-if",
- "cpufeatures 0.3.0",
-]
-
 [[package]]
 name = "keccak-asm"
 version = "0.1.5"
@@ -3035,6 +2972,9 @@ name = "lazy_static"
 version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+dependencies = [
+ "spin",
+]

 [[package]]
 name = "leb128fmt"
@@ -3233,34 +3173,6 @@ dependencies = [
 "windows-sys 0.61.2",
 ]

-[[package]]
-name = "ml-dsa"
-version = "0.1.0-rc.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f5b2bb0ad6fa2b40396775bd56f51345171490fef993f46f91a876ecdbdaea55"
-dependencies = [
- "const-oid 0.10.2",
- "ctutils",
- "hybrid-array",
- "module-lattice",
- "pkcs8 0.11.0-rc.11",
- "rand_core 0.10.0",
- "sha3 0.11.0",
- "signature 3.0.0-rc.10",
- "zeroize",
-]
-
-[[package]]
-name = "module-lattice"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "164eb3faeaecbd14b0b2a917c1b4d0c035097a9c559b0bed85c2cdd032bc8faa"
-dependencies = [
- "hybrid-array",
- "num-traits",
- "zeroize",
-]
-
 [[package]]
 name = "multimap"
 version = "0.10.1"
@@ -3302,6 +3214,23 @@ dependencies = [
 "num-traits",
 ]

+[[package]]
+name = "num-bigint-dig"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e661dda6640fad38e827a6d4a310ff4763082116fe217f279885c97f511bb0b7"
+dependencies = [
+ "lazy_static",
+ "libm",
+ "num-integer",
+ "num-iter",
+ "num-traits",
+ "rand 0.8.5",
+ "serde",
+ "smallvec",
+ "zeroize",
+]
+
 [[package]]
 name = "num-conv"
 version = "0.2.0"
@@ -3317,6 +3246,17 @@ dependencies = [
 "num-traits",
 ]

+[[package]]
+name = "num-iter"
+version = "0.1.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1429034a0490724d0075ebb2bc9e875d6503c3cf69e235a8941aa757d83ef5bf"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -3486,6 +3426,15 @@ dependencies = [
 "serde_core",
 ]

+[[package]]
+name = "pem-rfc7468"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88b39c9bfcfc231068454382784bb460aae594343fb030d46e9f50a645418412"
+dependencies = [
+ "base64ct",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"
@@ -3545,24 +3494,25 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"

+[[package]]
+name = "pkcs1"
+version = "0.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8ffb9f10fa047879315e6625af03c164b16962a5368d724ed16323b68ace47f"
+dependencies = [
+ "der",
+ "pkcs8",
+ "spki",
+]
+
 [[package]]
 name = "pkcs8"
 version = "0.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f950b2377845cebe5cf8b5165cb3cc1a5e0fa5cfa3e1f7f55707d8fd82e0a7b7"
 dependencies = [
- "der 0.7.10",
- "spki 0.7.3",
-]
-
-[[package]]
-name = "pkcs8"
-version = "0.11.0-rc.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "12922b6296c06eb741b02d7b5161e3aaa22864af38dfa025a1a3ba3f68c84577"
-dependencies = [
- "der 0.8.0",
- "spki 0.8.0",
+ "der",
+ "spki",
 ]

 [[package]]
@@ -4202,6 +4152,28 @@ dependencies = [
 "rustc-hex",
 ]

+[[package]]
+name = "rsa"
+version = "0.9.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8573f03f5883dcaebdfcf4725caa1ecb9c15b2ef50c43a07b816e06799bb12d"
+dependencies = [
+ "const-oid",
+ "digest 0.10.7",
+ "num-bigint-dig",
+ "num-integer",
+ "num-traits",
+ "pkcs1",
+ "pkcs8",
+ "rand_core 0.6.4",
+ "serde",
+ "sha2 0.10.9",
+ "signature 2.2.0",
+ "spki",
+ "subtle",
+ "zeroize",
+]
+
 [[package]]
 name = "rsqlite-vfs"
 version = "0.1.0"
@@ -4441,9 +4413,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d3e97a565f76233a6003f9f5c54be1d9c5bdfa3eccfb189469f11ec4901c47dc"
 dependencies = [
 "base16ct",
- "der 0.7.10",
+ "der",
 "generic-array",
- "pkcs8 0.10.2",
+ "pkcs8",
 "serdect",
 "subtle",
 "zeroize",
@@ -4637,17 +4609,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "75872d278a8f37ef87fa0ddbda7802605cb18344497949862c0d4dcb291eba60"
 dependencies = [
 "digest 0.10.7",
- "keccak 0.1.6",
-]
-
-[[package]]
-name = "sha3"
-version = "0.11.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be176f1a57ce4e3d31c1a166222d9768de5954f811601fb7ca06fc8203905ce1"
-dependencies = [
- "digest 0.11.2",
- "keccak 0.2.0",
+ "keccak",
 ]

 [[package]]
@@ -4700,10 +4662,6 @@ name = "signature"
 version = "3.0.0-rc.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f1880df446116126965eeec169136b2e0251dba37c6223bcc819569550edea3"
-dependencies = [
- "digest 0.11.2",
- "rand_core 0.10.0",
-]

 [[package]]
 name = "simd-adler32"
@@ -4763,6 +4721,12 @@ dependencies = [
 "windows-sys 0.61.2",
 ]

+[[package]]
+name = "spin"
+version = "0.9.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
+
 [[package]]
 name = "spki"
 version = "0.7.3"
@@ -4770,17 +4734,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d91ed6c858b01f942cd56b37a94b3e0a1798290327d1236e4d9cf4eaca44d29d"
 dependencies = [
 "base64ct",
- "der 0.7.10",
-]
-
-[[package]]
-name = "spki"
-version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d9efca8738c78ee9484207732f728b1ef517bbb1833d6fc0879ca898a522f6f"
-dependencies = [
- "base64ct",
- "der 0.8.0",
+ "der",
 ]

 [[package]]
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -20,7 +20,7 @@ tokio = { version = "1.50.0", features = ["full"] }
 ed25519-dalek = { version = "3.0.0-pre.6", features = ["rand_core"] }
 chrono = { version = "0.4.44", features = ["serde"] }
 rand = "0.10.0"
-rustls = { version = "0.23.37", features = ["aws-lc-rs", "logging", "prefer-post-quantum", "std"], default-features = false }
+rustls = { version = "0.23.37", features = ["aws-lc-rs"] }
 smlang = "0.8.0"
 thiserror = "2.0.18"
 async-trait = "0.1.89"
@@ -45,6 +45,3 @@ spki = "0.7"
 prost = "0.14.3"
 miette = { version = "7.6.0", features = ["fancy", "serde"] }
 mutants = "0.0.4"
-ml-dsa = { version = "0.1.0-rc.8", features = ["zeroize"] }
-base64 = "0.22.1"
-hmac = "0.12.1"
--- a/server/clippy.toml
+++ b/server/clippy.toml
@@ -6,4 +6,6 @@ disallowed-methods = [
    { path = "rsa::RsaPrivateKey::decrypt_blinded", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). Only PSS signing/verification is permitted." },
    { path = "rsa::traits::Decryptor::decrypt", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). This blocks decrypt() on rsa::{pkcs1v15,oaep}::DecryptingKey." },
    { path = "rsa::traits::RandomizedDecryptor::decrypt_with_rng", reason = "RSA decryption is forbidden (RUSTSEC-2023-0071 Marvin Attack). This blocks decrypt_with_rng() on rsa::{pkcs1v15,oaep}::DecryptingKey." },
+   
+    { path = "arbiter_server::crypto::integrity::v1::lookup_verified_allow_unavailable", reason = "This function allows integrity checks to be bypassed when vault key material is unavailable, which can lead to silent security failures if used incorrectly. It should only be used in specific contexts where this behavior is acceptable, and its use should be carefully audited." },
 ]
--- a/server/crates/arbiter-client/Cargo.toml
+++ b/server/crates/arbiter-client/Cargo.toml
@@ -13,12 +13,12 @@ evm = ["dep:alloy"]

 [dependencies]
 arbiter-proto.path = "../arbiter-proto"
-arbiter-crypto.path = "../arbiter-crypto"
 alloy = { workspace = true, optional = true }
 tonic.workspace = true
 tonic.features = ["tls-aws-lc"]
 tokio.workspace = true
 tokio-stream.workspace = true
+ed25519-dalek.workspace = true
 thiserror.workspace = true
 http = "1.4.0"
 rustls-webpki = { version = "0.103.10", features = ["aws-lc-rs"] }
--- a/server/crates/arbiter-client/src/auth.rs
+++ b/server/crates/arbiter-client/src/auth.rs
@@ -1,6 +1,5 @@
-use arbiter_crypto::authn::{CLIENT_CONTEXT, SigningKey, format_challenge};
 use arbiter_proto::{
-    ClientMetadata,
+    ClientMetadata, format_challenge,
    proto::{
        client::{
            ClientRequest,
@@ -15,6 +14,7 @@ use arbiter_proto::{
        shared::ClientInfo as ProtoClientInfo,
    },
 };
+use ed25519_dalek::Signer as _;

 use crate::{
    storage::StorageError,
@@ -54,14 +54,14 @@ fn map_auth_result(code: i32) -> AuthError {
 async fn send_auth_challenge_request(
    transport: &mut ClientTransport,
    metadata: ClientMetadata,
-    key: &SigningKey,
+    key: &ed25519_dalek::SigningKey,
 ) -> std::result::Result<(), AuthError> {
    transport
        .send(ClientRequest {
            request_id: next_request_id(),
            payload: Some(ClientRequestPayload::Auth(proto_auth::Request {
                payload: Some(AuthRequestPayload::ChallengeRequest(AuthChallengeRequest {
-                    pubkey: key.public_key().to_bytes(),
+                    pubkey: key.verifying_key().to_bytes().to_vec(),
                    client_info: Some(ProtoClientInfo {
                        name: metadata.name,
                        description: metadata.description,
@@ -95,14 +95,11 @@ async fn receive_auth_challenge(

 async fn send_auth_challenge_solution(
    transport: &mut ClientTransport,
-    key: &SigningKey,
+    key: &ed25519_dalek::SigningKey,
    challenge: AuthChallenge,
 ) -> std::result::Result<(), AuthError> {
    let challenge_payload = format_challenge(challenge.nonce, &challenge.pubkey);
-    let signature = key
-        .sign_message(&challenge_payload, CLIENT_CONTEXT)
-        .map_err(|_| AuthError::UnexpectedAuthResponse)?
-        .to_bytes();
+    let signature = key.sign(&challenge_payload).to_bytes().to_vec();

    transport
        .send(ClientRequest {
@@ -143,7 +140,7 @@ async fn receive_auth_confirmation(
 pub(crate) async fn authenticate(
    transport: &mut ClientTransport,
    metadata: ClientMetadata,
-    key: &SigningKey,
+    key: &ed25519_dalek::SigningKey,
 ) -> std::result::Result<(), AuthError> {
    send_auth_challenge_request(transport, metadata, key).await?;
    let challenge = receive_auth_challenge(transport).await?;
--- a/server/crates/arbiter-client/src/client.rs
+++ b/server/crates/arbiter-client/src/client.rs
@@ -1,4 +1,3 @@
-use arbiter_crypto::authn::SigningKey;
 use arbiter_proto::{
    ClientMetadata, proto::arbiter_service_client::ArbiterServiceClient, url::ArbiterUrl,
 };
@@ -61,7 +60,7 @@ impl ArbiterClient {
    pub async fn connect_with_key(
        url: ArbiterUrl,
        metadata: ClientMetadata,
-        key: SigningKey,
+        key: ed25519_dalek::SigningKey,
    ) -> Result<Self, Error> {
        let anchor = webpki::anchor_from_trusted_cert(&url.ca_cert)?.to_owned();
        let tls = ClientTlsConfig::new().trust_anchor(anchor);
--- a/server/crates/arbiter-client/src/storage.rs
+++ b/server/crates/arbiter-client/src/storage.rs
@@ -1,4 +1,3 @@
-use arbiter_crypto::authn::SigningKey;
 use arbiter_proto::home_path;
 use std::path::{Path, PathBuf};

@@ -12,7 +11,7 @@ pub enum StorageError {
 }

 pub trait SigningKeyStorage {
-    fn load_or_create(&self) -> std::result::Result<SigningKey, StorageError>;
+    fn load_or_create(&self) -> std::result::Result<ed25519_dalek::SigningKey, StorageError>;
 }

 #[derive(Debug, Clone)]
@@ -21,7 +20,7 @@ pub struct FileSigningKeyStorage {
 }

 impl FileSigningKeyStorage {
-    pub const DEFAULT_FILE_NAME: &str = "sdk_client_ml_dsa.key";
+    pub const DEFAULT_FILE_NAME: &str = "sdk_client_ed25519.key";

    pub fn new(path: impl Into<PathBuf>) -> Self {
        Self { path: path.into() }
@@ -31,7 +30,7 @@ impl FileSigningKeyStorage {
        Ok(Self::new(home_path()?.join(Self::DEFAULT_FILE_NAME)))
    }

-    fn read_key(path: &Path) -> std::result::Result<SigningKey, StorageError> {
+    fn read_key(path: &Path) -> std::result::Result<ed25519_dalek::SigningKey, StorageError> {
        let bytes = std::fs::read(path)?;
        let raw: [u8; 32] =
            bytes
@@ -40,12 +39,12 @@ impl FileSigningKeyStorage {
                    expected: 32,
                    actual: v.len(),
                })?;
-        Ok(SigningKey::from_seed(raw))
+        Ok(ed25519_dalek::SigningKey::from_bytes(&raw))
    }
 }

 impl SigningKeyStorage for FileSigningKeyStorage {
-    fn load_or_create(&self) -> std::result::Result<SigningKey, StorageError> {
+    fn load_or_create(&self) -> std::result::Result<ed25519_dalek::SigningKey, StorageError> {
        if let Some(parent) = self.path.parent() {
            std::fs::create_dir_all(parent)?;
        }
@@ -54,8 +53,8 @@ impl SigningKeyStorage for FileSigningKeyStorage {
            return Self::read_key(&self.path);
        }

-        let key = SigningKey::generate();
-        let raw_key = key.to_seed();
+        let key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+        let raw_key = key.to_bytes();

        // Use create_new to prevent accidental overwrite if another process creates the key first.
        match std::fs::OpenOptions::new()
@@ -104,7 +103,7 @@ mod tests {
            .load_or_create()
            .expect("second load_or_create should read same key");

-        assert_eq!(key_a.to_seed(), key_b.to_seed());
+        assert_eq!(key_a.to_bytes(), key_b.to_bytes());
        assert!(path.exists());

        std::fs::remove_file(path).expect("temp key file should be removable");
--- a/server/crates/arbiter-client/src/wallets/evm.rs
+++ b/server/crates/arbiter-client/src/wallets/evm.rs
@@ -59,6 +59,10 @@ pub struct ArbiterEvmWallet {
 }

 impl ArbiterEvmWallet {
+    #[expect(
+        dead_code,
+        reason = "constructor may be used in future extensions, e.g. to support wallet listing"
+    )]
    pub(crate) fn new(transport: Arc<Mutex<ClientTransport>>, address: Address) -> Self {
        Self {
            transport,
--- a/server/crates/arbiter-crypto/.gitignore
+++ b/server/crates/arbiter-crypto/.gitignore
@@ -1 +0,0 @@
-/target
--- a/server/crates/arbiter-crypto/Cargo.toml
+++ b/server/crates/arbiter-crypto/Cargo.toml
@@ -1,21 +0,0 @@
-[package]
-name = "arbiter-crypto"
-version = "0.1.0"
-edition = "2024"
-
-[dependencies]
-ml-dsa = {workspace = true, optional = true }
-rand = {workspace = true, optional = true}
-base64 = {workspace = true, optional = true }
-memsafe = {version = "0.4.0", optional = true}
-hmac.workspace = true
-alloy.workspace = true
-chrono.workspace = true
-
-[lints]
-workspace = true
-
-[features]
-default = ["authn", "safecell"]
-authn = ["dep:ml-dsa", "dep:rand", "dep:base64"]
-safecell = ["dep:memsafe"]
--- a/server/crates/arbiter-crypto/src/authn/mod.rs
+++ b/server/crates/arbiter-crypto/src/authn/mod.rs
@@ -1,2 +0,0 @@
-pub mod v1;
-pub use v1::*;
--- a/server/crates/arbiter-crypto/src/authn/v1.rs
+++ b/server/crates/arbiter-crypto/src/authn/v1.rs
@@ -1,193 +0,0 @@
-use base64::{Engine as _, prelude::BASE64_STANDARD};
-use hmac::digest::Digest;
-use ml_dsa::{
-    EncodedVerifyingKey, Error, KeyGen, MlDsa87, Seed, Signature as MlDsaSignature,
-    SigningKey as MlDsaSigningKey, VerifyingKey as MlDsaVerifyingKey, signature::Keypair as _,
-};
-
-pub static CLIENT_CONTEXT: &[u8] = b"arbiter_client";
-pub static USERAGENT_CONTEXT: &[u8] = b"arbiter_user_agent";
-
-pub fn format_challenge(nonce: i32, pubkey: &[u8]) -> Vec<u8> {
-    let concat_form = format!("{}:{}", nonce, BASE64_STANDARD.encode(pubkey));
-    concat_form.into_bytes()
-}
-
-pub type KeyParams = MlDsa87;
-
-#[derive(Clone, Debug, PartialEq)]
-pub struct PublicKey(Box<MlDsaVerifyingKey<KeyParams>>);
-
-impl crate::hashing::Hashable for PublicKey {
-    fn hash<H: Digest>(&self, hasher: &mut H) {
-        hasher.update(self.to_bytes());
-    }
-}
-
-#[derive(Clone, Debug, PartialEq)]
-pub struct Signature(Box<MlDsaSignature<KeyParams>>);
-
-#[derive(Debug)]
-pub struct SigningKey(Box<MlDsaSigningKey<KeyParams>>);
-
-impl PublicKey {
-    pub fn to_bytes(&self) -> Vec<u8> {
-        self.0.encode().0.to_vec()
-    }
-
-    pub fn verify(&self, nonce: i32, context: &[u8], signature: &Signature) -> bool {
-        self.0.verify_with_context(
-            &format_challenge(nonce, &self.to_bytes()),
-            context,
-            &signature.0,
-        )
-    }
-}
-
-impl Signature {
-    pub fn to_bytes(&self) -> Vec<u8> {
-        self.0.encode().0.to_vec()
-    }
-}
-
-impl SigningKey {
-    pub fn generate() -> Self {
-        Self(Box::new(KeyParams::key_gen(&mut rand::rng())))
-    }
-
-    pub fn from_seed(seed: [u8; 32]) -> Self {
-        Self(Box::new(KeyParams::from_seed(&Seed::from(seed))))
-    }
-
-    pub fn to_seed(&self) -> [u8; 32] {
-        self.0.to_seed().into()
-    }
-
-    pub fn public_key(&self) -> PublicKey {
-        self.0.verifying_key().into()
-    }
-
-    pub fn sign_message(&self, message: &[u8], context: &[u8]) -> Result<Signature, Error> {
-        self.0
-            .signing_key()
-            .sign_deterministic(message, context)
-            .map(Into::into)
-    }
-
-    pub fn sign_challenge(&self, nonce: i32, context: &[u8]) -> Result<Signature, Error> {
-        self.sign_message(
-            &format_challenge(nonce, &self.public_key().to_bytes()),
-            context,
-        )
-    }
-}
-
-impl From<MlDsaVerifyingKey<KeyParams>> for PublicKey {
-    fn from(value: MlDsaVerifyingKey<KeyParams>) -> Self {
-        Self(Box::new(value))
-    }
-}
-
-impl From<MlDsaSignature<KeyParams>> for Signature {
-    fn from(value: MlDsaSignature<KeyParams>) -> Self {
-        Self(Box::new(value))
-    }
-}
-
-impl From<MlDsaSigningKey<KeyParams>> for SigningKey {
-    fn from(value: MlDsaSigningKey<KeyParams>) -> Self {
-        Self(Box::new(value))
-    }
-}
-
-impl TryFrom<Vec<u8>> for PublicKey {
-    type Error = ();
-
-    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
-        Self::try_from(value.as_slice())
-    }
-}
-
-impl TryFrom<&'_ [u8]> for PublicKey {
-    type Error = ();
-
-    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
-        let encoded = EncodedVerifyingKey::<KeyParams>::try_from(value).map_err(|_| ())?;
-        Ok(Self(Box::new(MlDsaVerifyingKey::decode(&encoded))))
-    }
-}
-
-impl TryFrom<Vec<u8>> for Signature {
-    type Error = ();
-
-    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
-        Self::try_from(value.as_slice())
-    }
-}
-
-impl TryFrom<&'_ [u8]> for Signature {
-    type Error = ();
-
-    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
-        MlDsaSignature::try_from(value)
-            .map(|sig| Self(Box::new(sig)))
-            .map_err(|_| ())
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use ml_dsa::{KeyGen, MlDsa87, signature::Keypair as _};
-
-    use super::{CLIENT_CONTEXT, PublicKey, Signature, SigningKey, USERAGENT_CONTEXT};
-
-    #[test]
-    fn public_key_round_trip_decodes() {
-        let key = MlDsa87::key_gen(&mut rand::rng());
-        let encoded = PublicKey::from(key.verifying_key()).to_bytes();
-
-        let decoded = PublicKey::try_from(encoded.as_slice()).expect("public key should decode");
-
-        assert_eq!(decoded, PublicKey::from(key.verifying_key()));
-    }
-
-    #[test]
-    fn signature_round_trip_decodes() {
-        let key = SigningKey::generate();
-        let signature = key
-            .sign_message(b"challenge", CLIENT_CONTEXT)
-            .expect("signature should be created");
-
-        let decoded =
-            Signature::try_from(signature.to_bytes().as_slice()).expect("signature should decode");
-
-        assert_eq!(decoded, signature);
-    }
-
-    #[test]
-    fn challenge_verification_uses_context_and_canonical_key_bytes() {
-        let key = SigningKey::generate();
-        let public_key = key.public_key();
-        let nonce = 17;
-        let signature = key
-            .sign_challenge(nonce, CLIENT_CONTEXT)
-            .expect("signature should be created");
-
-        assert!(public_key.verify(nonce, CLIENT_CONTEXT, &signature));
-        assert!(!public_key.verify(nonce, USERAGENT_CONTEXT, &signature));
-    }
-
-    #[test]
-    fn signing_key_round_trip_seed_preserves_public_key_and_signing() {
-        let original = SigningKey::generate();
-        let restored = SigningKey::from_seed(original.to_seed());
-
-        assert_eq!(restored.public_key(), original.public_key());
-
-        let signature = restored
-            .sign_challenge(9, CLIENT_CONTEXT)
-            .expect("signature should be created");
-
-        assert!(restored.public_key().verify(9, CLIENT_CONTEXT, &signature));
-    }
-}
--- a/server/crates/arbiter-crypto/src/lib.rs
+++ b/server/crates/arbiter-crypto/src/lib.rs
@@ -1,5 +0,0 @@
-#[cfg(feature = "authn")]
-pub mod authn;
-pub mod hashing;
-#[cfg(feature = "safecell")]
-pub mod safecell;
--- a/server/crates/arbiter-macros/Cargo.toml
+++ b/server/crates/arbiter-macros/Cargo.toml
@@ -1,18 +0,0 @@
-[package]
-name = "arbiter-macros"
-version = "0.1.0"
-edition = "2024"
-
-[lib]
-proc-macro = true
-
-[dependencies]
-proc-macro2 = "1.0"
-quote = "1.0"
-syn = { version = "2.0", features = ["derive", "fold", "full", "visit-mut"] }
-
-[dev-dependencies]
-arbiter-crypto = { path = "../arbiter-crypto" }
-
-[lints]
-workspace = true
--- a/server/crates/arbiter-macros/src/hashable.rs
+++ b/server/crates/arbiter-macros/src/hashable.rs
@@ -1,133 +0,0 @@
-use proc_macro2::{Span, TokenStream, TokenTree};
-use quote::quote;
-use syn::parse_quote;
-use syn::spanned::Spanned;
-use syn::{DataStruct, DeriveInput, Fields, Generics, Index};
-
-use crate::utils::{HASHABLE_TRAIT_PATH, HMAC_DIGEST_PATH};
-
-pub(crate) fn derive(input: &DeriveInput) -> TokenStream {
-    match &input.data {
-        syn::Data::Struct(struct_data) => hashable_struct(input, struct_data),
-        syn::Data::Enum(_) => {
-            syn::Error::new_spanned(input, "Hashable can currently be derived only for structs")
-                .to_compile_error()
-        }
-        syn::Data::Union(_) => {
-            syn::Error::new_spanned(input, "Hashable cannot be derived for unions")
-                .to_compile_error()
-        }
-    }
-}
-
-fn hashable_struct(input: &DeriveInput, struct_data: &syn::DataStruct) -> TokenStream {
-    let ident = &input.ident;
-    let hashable_trait = HASHABLE_TRAIT_PATH.to_path();
-    let hmac_digest = HMAC_DIGEST_PATH.to_path();
-    let generics = add_hashable_bounds(input.generics.clone(), &hashable_trait);
-    let field_accesses = collect_field_accesses(struct_data);
-    let hash_calls = build_hash_calls(&field_accesses, &hashable_trait);
-
-    let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
-
-    quote! {
-        #[automatically_derived]
-        impl #impl_generics #hashable_trait for #ident #ty_generics #where_clause {
-            fn hash<H: #hmac_digest>(&self, hasher: &mut H) {
-                #(#hash_calls)*
-            }
-        }
-    }
-}
-
-fn add_hashable_bounds(mut generics: Generics, hashable_trait: &syn::Path) -> Generics {
-    for type_param in generics.type_params_mut() {
-        type_param.bounds.push(parse_quote!(#hashable_trait));
-    }
-
-    generics
-}
-
-struct FieldAccess {
-    access: TokenStream,
-    span: Span,
-}
-
-fn collect_field_accesses(struct_data: &DataStruct) -> Vec<FieldAccess> {
-    match &struct_data.fields {
-        Fields::Named(fields) => {
-            // Keep deterministic alphabetical order for named fields.
-            // Do not remove this sort, because it keeps hash output stable regardless of source order.
-            let mut named_fields = fields
-                .named
-                .iter()
-                .map(|field| {
-                    let name = field
-                        .ident
-                        .as_ref()
-                        .expect("Fields::Named(fields) must have names")
-                        .clone();
-                    (name.to_string(), name)
-                })
-                .collect::<Vec<_>>();
-
-            named_fields.sort_by(|a, b| a.0.cmp(&b.0));
-
-            named_fields
-                .into_iter()
-                .map(|(_, name)| FieldAccess {
-                    access: quote! { #name },
-                    span: name.span(),
-                })
-                .collect()
-        }
-        Fields::Unnamed(fields) => fields
-            .unnamed
-            .iter()
-            .enumerate()
-            .map(|(i, field)| FieldAccess {
-                access: {
-                    let index = Index::from(i);
-                    quote! { #index }
-                },
-                span: field.ty.span(),
-            })
-            .collect(),
-        Fields::Unit => Vec::new(),
-    }
-}
-
-fn build_hash_calls(
-    field_accesses: &[FieldAccess],
-    hashable_trait: &syn::Path,
-) -> Vec<TokenStream> {
-    field_accesses
-        .iter()
-        .map(|field| {
-            let access = &field.access;
-            let call = quote! {
-                #hashable_trait::hash(&self.#access, hasher);
-            };
-
-            respan(call, field.span)
-        })
-        .collect()
-}
-
-/// Recursively set span on all tokens, including interpolated ones.
-fn respan(tokens: TokenStream, span: Span) -> TokenStream {
-    tokens
-        .into_iter()
-        .map(|tt| match tt {
-            TokenTree::Group(g) => {
-                let mut new = proc_macro2::Group::new(g.delimiter(), respan(g.stream(), span));
-                new.set_span(span);
-                TokenTree::Group(new)
-            }
-            mut other => {
-                other.set_span(span);
-                other
-            }
-        })
-        .collect()
-}
--- a/server/crates/arbiter-macros/src/lib.rs
+++ b/server/crates/arbiter-macros/src/lib.rs
@@ -1,10 +0,0 @@
-use syn::{DeriveInput, parse_macro_input};
-
-mod hashable;
-mod utils;
-
-#[proc_macro_derive(Hashable)]
-pub fn derive_hashable(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
-    let input = parse_macro_input!(input as DeriveInput);
-    hashable::derive(&input).into()
-}
--- a/server/crates/arbiter-macros/src/utils.rs
+++ b/server/crates/arbiter-macros/src/utils.rs
@@ -1,19 +0,0 @@
-pub struct ToPath(pub &'static str);
-
-impl ToPath {
-    pub fn to_path(&self) -> syn::Path {
-        syn::parse_str(self.0).expect("Invalid path")
-    }
-}
-
-macro_rules! ensure_path {
-    ($path:path) => {{
-        #[cfg(test)]
-        #[expect(unused_imports)]
-        use $path as _;
-        ToPath(stringify!($path))
-    }};
-}
-
-pub const HASHABLE_TRAIT_PATH: ToPath = ensure_path!(::arbiter_crypto::hashing::Hashable);
-pub const HMAC_DIGEST_PATH: ToPath = ensure_path!(::arbiter_crypto::hashing::Digest);
--- a/server/crates/arbiter-proto/Cargo.toml
+++ b/server/crates/arbiter-proto/Cargo.toml
@@ -17,7 +17,7 @@ url = "2.5.8"
 miette.workspace = true
 thiserror.workspace = true
 rustls-pki-types.workspace = true
-base64.workspace = true
+base64 = "0.22.1"
 prost-types.workspace = true
 tracing.workspace = true
 async-trait.workspace = true
--- a/server/crates/arbiter-proto/src/lib.rs
+++ b/server/crates/arbiter-proto/src/lib.rs
@@ -1,6 +1,8 @@
 pub mod transport;
 pub mod url;

+use base64::{Engine, prelude::BASE64_STANDARD};
+
 pub mod proto {
    tonic::include_proto!("arbiter");

@@ -82,3 +84,8 @@ pub fn home_path() -> Result<std::path::PathBuf, std::io::Error> {

    Ok(arbiter_home)
 }
+
+pub fn format_challenge(nonce: i32, pubkey: &[u8]) -> Vec<u8> {
+    let concat_form = format!("{}:{}", nonce, BASE64_STANDARD.encode(pubkey));
+    concat_form.into_bytes()
+}
--- a/server/crates/arbiter-server/Cargo.toml
+++ b/server/crates/arbiter-server/Cargo.toml
@@ -16,9 +16,9 @@ diesel-async = { version = "0.8.0", features = [
    "sqlite",
    "tokio",
 ] }
+ed25519-dalek.workspace = true
+ed25519-dalek.features = ["serde"]
 arbiter-proto.path = "../arbiter-proto"
-arbiter-crypto.path = "../arbiter-crypto"
-arbiter-macros.path = "../arbiter-macros"
 tracing.workspace = true
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tonic.workspace = true
@@ -37,15 +37,21 @@ dashmap = "6.1.0"
 rand.workspace = true
 rcgen.workspace = true
 chrono.workspace = true
+memsafe = "0.4.0"
 zeroize = { version = "1.8.2", features = ["std", "simd"] }
 kameo.workspace = true
+x25519-dalek.workspace = true
 chacha20poly1305 = { version = "0.10.1", features = ["std"] }
 argon2 = { version = "0.5.3", features = ["zeroize"] }
 restructed = "0.2.2"
 strum = { version = "0.28.0", features = ["derive"] }
 pem = "3.0.6"
+k256.workspace = true
+k256.features = ["serde"]
+rsa.workspace = true
+rsa.features = ["serde"]
 sha2.workspace = true
-hmac.workspace = true
+hmac = "0.12"
 spki.workspace = true
 alloy.workspace = true
 prost-types.workspace = true
@@ -55,10 +61,6 @@ anyhow = "1.0.102"
 serde_with = "3.18.0"
 mutants.workspace = true
 subtle = "2.6.1"
-ml-dsa.workspace = true
-ed25519-dalek.workspace = true
-x25519-dalek.workspace = true
-k256.workspace = true

 [dev-dependencies]
 insta = "1.46.3"
--- a/server/crates/arbiter-server/migrations/2026-02-14-171124-0000_init/up.sql
+++ b/server/crates/arbiter-server/migrations/2026-02-14-171124-0000_init/up.sql
@@ -47,7 +47,7 @@ create table if not exists useragent_client (
    id integer not null primary key,
    nonce integer not null default(1), -- used for auth challenge
    public_key blob not null,
-    key_type integer not null default(1),
+    key_type integer not null default(1), -- 1=Ed25519, 2=ECDSA(secp256k1)
    created_at integer not null default(unixepoch ('now')),
    updated_at integer not null default(unixepoch ('now'))
 ) STRICT;
--- a/server/crates/arbiter-server/src/actors/client/auth.rs
+++ b/server/crates/arbiter-server/src/actors/client/auth.rs
@@ -1,6 +1,5 @@
-use arbiter_crypto::authn::{self, CLIENT_CONTEXT};
 use arbiter_proto::{
-    ClientMetadata,
+    ClientMetadata, format_challenge,
    transport::{Bi, expect_message},
 };
 use chrono::Utc;
@@ -9,6 +8,7 @@ use diesel::{
    dsl::insert_into, update,
 };
 use diesel_async::RunQueryDsl as _;
+use ed25519_dalek::{Signature, VerifyingKey};
 use kameo::{actor::ActorRef, error::SendError};
 use tracing::error;

@@ -18,7 +18,7 @@ use crate::{
        flow_coordinator::{self, RequestClientApproval},
        keyholder::KeyHolder,
    },
-    crypto::integrity::{self, AttestationStatus},
+    crypto::integrity::{self},
    db::{
        self,
        models::{ProgramClientMetadata, SqliteTimestamp},
@@ -62,20 +62,17 @@ pub enum ApproveError {
 #[derive(Debug, Clone)]
 pub enum Inbound {
    AuthChallengeRequest {
-        pubkey: authn::PublicKey,
+        pubkey: VerifyingKey,
        metadata: ClientMetadata,
    },
    AuthChallengeSolution {
-        signature: authn::Signature,
+        signature: Signature,
    },
 }

 #[derive(Debug, Clone)]
 pub enum Outbound {
-    AuthChallenge {
-        pubkey: authn::PublicKey,
-        nonce: i32,
-    },
+    AuthChallenge { pubkey: VerifyingKey, nonce: i32 },
    AuthSuccess,
 }

@@ -83,9 +80,9 @@ pub enum Outbound {
 /// Returns `None` if the pubkey is not registered.
 async fn get_current_nonce_and_id(
    db: &db::DatabasePool,
-    pubkey: &authn::PublicKey,
+    pubkey: &VerifyingKey,
 ) -> Result<Option<(i32, i32)>, Error> {
-    let pubkey_bytes = pubkey.to_bytes();
+    let pubkey_bytes = pubkey.as_bytes().to_vec();
    let mut conn = db.get().await.map_err(|e| {
        error!(error = ?e, "Database pool error");
        Error::DatabasePoolUnavailable
@@ -105,7 +102,7 @@ async fn get_current_nonce_and_id(
 async fn verify_integrity(
    db: &db::DatabasePool,
    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
+    pubkey: &VerifyingKey,
 ) -> Result<(), Error> {
    let mut db_conn = db.get().await.map_err(|e| {
        error!(error = ?e, "Database pool error");
@@ -117,11 +114,11 @@ async fn verify_integrity(
        Error::DatabaseOperationFailed
    })?;

-    let attestation = integrity::verify_entity(
+    integrity::verify_entity(
        &mut db_conn,
        keyholder,
        &ClientCredentials {
-            pubkey: pubkey.clone(),
+            pubkey: *pubkey,
            nonce,
        },
        id,
@@ -132,11 +129,6 @@ async fn verify_integrity(
        Error::IntegrityCheckFailed
    })?;

-    if attestation != AttestationStatus::Attested {
-        error!("Integrity attestation unavailable for client {id}");
-        return Err(Error::IntegrityCheckFailed);
-    }
-
    Ok(())
 }

@@ -145,10 +137,9 @@ async fn verify_integrity(
 async fn create_nonce(
    db: &db::DatabasePool,
    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
+    pubkey: &VerifyingKey,
 ) -> Result<i32, Error> {
-    let pubkey_bytes = pubkey.to_bytes();
-    let pubkey = pubkey.clone();
+    let pubkey_bytes = pubkey.as_bytes().to_vec();

    let mut conn = db.get().await.map_err(|e| {
        error!(error = ?e, "Database pool error");
@@ -157,7 +148,6 @@ async fn create_nonce(

    conn.exclusive_transaction(|conn| {
        let keyholder = keyholder.clone();
-        let pubkey = pubkey.clone();
        Box::pin(async move {
            let (id, new_nonce): (i32, i32) = update(program_client::table)
                .filter(program_client::public_key.eq(&pubkey_bytes))
@@ -170,7 +160,7 @@ async fn create_nonce(
                conn,
                &keyholder,
                &ClientCredentials {
-                    pubkey: pubkey.clone(),
+                    pubkey: *pubkey,
                    nonce: new_nonce,
                },
                id,
@@ -213,11 +203,10 @@ async fn approve_new_client(
 async fn insert_client(
    db: &db::DatabasePool,
    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
+    pubkey: &VerifyingKey,
    metadata: &ClientMetadata,
 ) -> Result<i32, Error> {
    use crate::db::schema::{client_metadata, program_client};
-    let pubkey = pubkey.clone();
    let metadata = metadata.clone();

    let mut conn = db.get().await.map_err(|e| {
@@ -227,7 +216,6 @@ async fn insert_client(

    conn.exclusive_transaction(|conn| {
        let keyholder = keyholder.clone();
-        let pubkey = pubkey.clone();
        Box::pin(async move {
            const NONCE_START: i32 = 1;

@@ -243,7 +231,7 @@ async fn insert_client(

            let client_id = insert_into(program_client::table)
                .values((
-                    program_client::public_key.eq(pubkey.to_bytes()),
+                    program_client::public_key.eq(pubkey.as_bytes().to_vec()),
                    program_client::metadata_id.eq(metadata_id),
                    program_client::nonce.eq(NONCE_START),
                ))
@@ -256,7 +244,7 @@ async fn insert_client(
                conn,
                &keyholder,
                &ClientCredentials {
-                    pubkey: pubkey.clone(),
+                    pubkey: *pubkey,
                    nonce: NONCE_START,
                },
                client_id,
@@ -346,17 +334,14 @@ async fn sync_client_metadata(

 async fn challenge_client<T>(
    transport: &mut T,
-    pubkey: authn::PublicKey,
+    pubkey: VerifyingKey,
    nonce: i32,
 ) -> Result<(), Error>
 where
    T: Bi<Inbound, Result<Outbound, Error>> + ?Sized,
 {
    transport
-        .send(Ok(Outbound::AuthChallenge {
-            pubkey: pubkey.clone(),
-            nonce,
-        }))
+        .send(Ok(Outbound::AuthChallenge { pubkey, nonce }))
        .await
        .map_err(|e| {
            error!(error = ?e, "Failed to send auth challenge");
@@ -373,10 +358,12 @@ where
        Error::Transport
    })?;

-    if !pubkey.verify(nonce, CLIENT_CONTEXT, &signature) {
+    let formatted = format_challenge(nonce, pubkey.as_bytes());
+
+    pubkey.verify_strict(&formatted, &signature).map_err(|_| {
        error!("Challenge solution verification failed");
-        return Err(Error::InvalidChallengeSolution);
-    }
+        Error::InvalidChallengeSolution
+    })?;

    Ok(())
 }
@@ -398,7 +385,7 @@ where
            approve_new_client(
                &props.actors,
                ClientProfile {
-                    pubkey: pubkey.clone(),
+                    pubkey,
                    metadata: metadata.clone(),
                },
            )
--- a/server/crates/arbiter-server/src/actors/client/mod.rs
+++ b/server/crates/arbiter-server/src/actors/client/mod.rs
@@ -1,23 +1,21 @@
-use arbiter_crypto::authn;
 use arbiter_proto::{ClientMetadata, transport::Bi};
 use kameo::actor::Spawn;
 use tracing::{error, info};

 use crate::{
    actors::{GlobalActors, client::session::ClientSession},
-    crypto::integrity::Integrable,
+    crypto::integrity::{Integrable, hashing::Hashable},
    db,
 };

 #[derive(Debug, Clone)]
 pub struct ClientProfile {
-    pub pubkey: authn::PublicKey,
+    pub pubkey: ed25519_dalek::VerifyingKey,
    pub metadata: ClientMetadata,
 }

-#[derive(arbiter_macros::Hashable)]
 pub struct ClientCredentials {
-    pub pubkey: authn::PublicKey,
+    pub pubkey: ed25519_dalek::VerifyingKey,
    pub nonce: i32,
 }

@@ -25,6 +23,13 @@ impl Integrable for ClientCredentials {
    const KIND: &'static str = "client_credentials";
 }

+impl Hashable for ClientCredentials {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        hasher.update(self.pubkey.as_bytes());
+        self.nonce.hash(hasher);
+    }
+}
+
 pub struct ClientConnection {
    pub(crate) db: db::DatabasePool,
    pub(crate) actors: GlobalActors,
@@ -43,9 +48,7 @@ pub async fn connect_client<T>(mut props: ClientConnection, transport: &mut T)
 where
    T: Bi<auth::Inbound, Result<auth::Outbound, auth::Error>> + Send + ?Sized,
 {
-    let fut = auth::authenticate(&mut props, transport);
-    println!("authenticate future size: {}", std::mem::size_of_val(&fut));
-    match fut.await {
+    match auth::authenticate(&mut props, transport).await {
        Ok(client_id) => {
            ClientSession::spawn(ClientSession::new(props, client_id));
            info!("Client authenticated, session started");
--- a/server/crates/arbiter-server/src/actors/evm/mod.rs
+++ b/server/crates/arbiter-server/src/actors/evm/mod.rs
@@ -21,8 +21,8 @@ use crate::{
            ether_transfer::EtherTransfer, token_transfers::TokenTransfer,
        },
    },
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};

 pub use crate::evm::safe_signer;

@@ -136,7 +136,7 @@ impl EvmActor {
        &mut self,
        basic: SharedGrantSettings,
        grant: SpecificGrant,
-    ) -> Result<i32, Error> {
+    ) -> Result<integrity::Verified<i32>, Error> {
        match grant {
            SpecificGrant::EtherTransfer(settings) => self
                .engine
--- a/server/crates/arbiter-server/src/actors/keyholder/mod.rs
+++ b/server/crates/arbiter-server/src/actors/keyholder/mod.rs
@@ -9,17 +9,22 @@ use kameo::{Actor, Reply, messages};
 use strum::{EnumDiscriminants, IntoDiscriminant};
 use tracing::{error, info};

-use crate::crypto::{
-    KeyCell, derive_key,
-    encryption::v1::{self, Nonce},
-    integrity::v1::HmacSha256,
+use crate::{
+    crypto::{
+        KeyCell, derive_key,
+        encryption::v1::{self, Nonce},
+        integrity::v1::HmacSha256,
+    },
+    safe_cell::SafeCell,
 };
-use crate::db::{
-    self,
-    models::{self, RootKeyHistory},
-    schema::{self},
+use crate::{
+    db::{
+        self,
+        models::{self, RootKeyHistory},
+        schema::{self},
+    },
+    safe_cell::SafeCellHandle as _,
 };
-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};

 #[derive(Default, EnumDiscriminants)]
 #[strum_discriminants(derive(Reply), vis(pub), name(KeyHolderState))]
@@ -395,8 +400,10 @@ mod tests {

    use diesel_async::RunQueryDsl;

-    use crate::db::{self};
-    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+    use crate::{
+        db::{self},
+        safe_cell::SafeCell,
+    };

    use super::*;

--- a/server/crates/arbiter-server/src/actors/user_agent/auth.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/auth.rs
@@ -1,18 +1,18 @@
-use arbiter_crypto::authn;
 use arbiter_proto::transport::Bi;
 use tracing::error;

 use crate::actors::user_agent::{
-    UserAgentConnection,
+    AuthPublicKey, UserAgentConnection,
    auth::state::{AuthContext, AuthStateMachine},
 };
+
 mod state;
 use state::*;

 #[derive(Debug, Clone)]
 pub enum Inbound {
    AuthChallengeRequest {
-        pubkey: authn::PublicKey,
+        pubkey: AuthPublicKey,
        bootstrap_token: Option<String>,
    },
    AuthChallengeSolution {
@@ -30,17 +30,26 @@ pub enum Error {
 }

 impl Error {
-    fn internal(details: impl Into<String>) -> Self {
-        Self::Internal {
-            details: details.into(),
-        }
+    #[track_caller]
+    pub(super) fn internal(details: impl Into<String>, err: &impl std::fmt::Debug) -> Self {
+        let details = details.into();
+        let caller = std::panic::Location::caller();
+        error!(
+            caller_file = %caller.file(),
+            caller_line = caller.line(),
+            caller_column = caller.column(),
+            details = %details,
+            error = ?err,
+            "Internal error"
+        );
+
+        Self::Internal { details }
    }
 }

 impl From<diesel::result::Error> for Error {
    fn from(e: diesel::result::Error) -> Self {
-        error!(?e, "Database error");
-        Self::internal("Database error")
+        Self::internal("Database error", &e)
    }
 }

@@ -71,7 +80,7 @@ fn parse_auth_event(payload: Inbound) -> AuthEvents {
 pub async fn authenticate<T>(
    props: &mut UserAgentConnection,
    transport: T,
-) -> Result<authn::PublicKey, Error>
+) -> Result<AuthPublicKey, Error>
 where
    T: Bi<Inbound, Result<Outbound, Error>> + Send,
 {
--- a/server/crates/arbiter-server/src/actors/user_agent/auth/state.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/auth/state.rs
@@ -1,4 +1,3 @@
-use arbiter_crypto::authn::{self, USERAGENT_CONTEXT};
 use arbiter_proto::transport::Bi;
 use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, update};
 use diesel_async::{AsyncConnection, RunQueryDsl};
@@ -10,24 +9,24 @@ use crate::{
    actors::{
        bootstrap::ConsumeToken,
        keyholder::KeyHolder,
-        user_agent::{UserAgentConnection, UserAgentCredentials, auth::Outbound},
+        user_agent::{AuthPublicKey, UserAgentConnection, UserAgentCredentials, auth::Outbound},
    },
    crypto::integrity,
    db::{DatabasePool, schema::useragent_client},
 };

 pub struct ChallengeRequest {
-    pub pubkey: authn::PublicKey,
+    pub pubkey: AuthPublicKey,
 }

 pub struct BootstrapAuthRequest {
-    pub pubkey: authn::PublicKey,
+    pub pubkey: AuthPublicKey,
    pub token: String,
 }

 pub struct ChallengeContext {
    pub challenge_nonce: i32,
-    pub key: authn::PublicKey,
+    pub key: AuthPublicKey,
 }

 pub struct ChallengeSolution {
@@ -39,25 +38,26 @@ smlang::statemachine!(
    custom_error: true,
    transitions: {
        *Init + AuthRequest(ChallengeRequest) / async prepare_challenge = SentChallenge(ChallengeContext),
-        Init + BootstrapAuthRequest(BootstrapAuthRequest) / async verify_bootstrap_token = AuthOk(authn::PublicKey),
-        SentChallenge(ChallengeContext) + ReceivedSolution(ChallengeSolution) / async verify_solution = AuthOk(authn::PublicKey),
+        Init + BootstrapAuthRequest(BootstrapAuthRequest) / async verify_bootstrap_token = AuthOk(AuthPublicKey),
+        SentChallenge(ChallengeContext) + ReceivedSolution(ChallengeSolution) / async verify_solution = AuthOk(AuthPublicKey),
    }
 );

 /// Returns the current nonce, ready to use for the challenge nonce.
 async fn get_current_nonce_and_id(
    db: &DatabasePool,
-    key: &authn::PublicKey,
+    key: &AuthPublicKey,
 ) -> Result<(i32, i32), Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
+    let mut db_conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;
    db_conn
        .exclusive_transaction(|conn| {
            Box::pin(async move {
                useragent_client::table
-                    .filter(useragent_client::public_key.eq(key.to_bytes()))
+                    .filter(useragent_client::public_key.eq(key.to_stored_bytes()))
+                    .filter(useragent_client::key_type.eq(key.key_type()))
                    .select((useragent_client::id, useragent_client::nonce))
                    .first::<(i32, i32)>(conn)
                    .await
@@ -65,10 +65,7 @@ async fn get_current_nonce_and_id(
        })
        .await
        .optional()
-        .map_err(|e| {
-            error!(error = ?e, "Database error");
-            Error::internal("Database operation failed")
-        })?
+        .map_err(|e| Error::internal("Database operation failed", &e))?
        .ok_or_else(|| {
            error!(?key, "Public key not found in database");
            Error::UnregisteredPublicKey
@@ -78,16 +75,16 @@ async fn get_current_nonce_and_id(
 async fn verify_integrity(
    db: &DatabasePool,
    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
+    pubkey: &AuthPublicKey,
 ) -> Result<(), Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
+    let mut db_conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;

    let (id, nonce) = get_current_nonce_and_id(db, pubkey).await?;

-    let _result = integrity::verify_entity(
+    let attestation_status = integrity::check_entity_attestation(
        &mut db_conn,
        keyholder,
        &UserAgentCredentials {
@@ -97,36 +94,39 @@ async fn verify_integrity(
        id,
    )
    .await
-    .map_err(|e| {
-        error!(?e, "Integrity verification failed");
-        Error::internal("Integrity verification failed")
-    })?;
+    .map_err(|e| Error::internal("Integrity verification failed", &e))?;

-    Ok(())
+    use integrity::AttestationStatus as AS;
+    // SAFETY (policy): challenge auth must work in both vault states.
+    // While sealed, integrity checks can only report `Unavailable` because key material is not
+    // accessible. While unsealed, the same check can report `Attested`.
+    // This path intentionally accepts both outcomes to keep challenge auth available across state
+    // transitions; stricter verification is enforced in sensitive post-auth flows.
+    match attestation_status {
+        AS::Attested | AS::Unavailable => Ok(()),
+    }
 }

 async fn create_nonce(
    db: &DatabasePool,
    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
+    pubkey: &AuthPublicKey,
 ) -> Result<i32, Error> {
-    let mut db_conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
+    let mut db_conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;
    let new_nonce = db_conn
        .exclusive_transaction(|conn| {
            Box::pin(async move {
                let (id, new_nonce): (i32, i32) = update(useragent_client::table)
-                    .filter(useragent_client::public_key.eq(pubkey.to_bytes()))
+                    .filter(useragent_client::public_key.eq(pubkey.to_stored_bytes()))
+                    .filter(useragent_client::key_type.eq(pubkey.key_type()))
                    .set(useragent_client::nonce.eq(useragent_client::nonce + 1))
                    .returning((useragent_client::id, useragent_client::nonce))
                    .get_result(conn)
                    .await
-                    .map_err(|e| {
-                        error!(error = ?e, "Database error");
-                        Error::internal("Database operation failed")
-                    })?;
+                    .map_err(|e| Error::internal("Database operation failed", &e))?;

                integrity::sign_entity(
                    conn,
@@ -138,10 +138,7 @@ async fn create_nonce(
                    id,
                )
                .await
-                .map_err(|e| {
-                    error!(?e, "Integrity signature update failed");
-                    Error::internal("Database error")
-                })?;
+                .map_err(|e| Error::internal("Database error", &e))?;

                Result::<_, Error>::Ok(new_nonce)
            })
@@ -153,13 +150,14 @@ async fn create_nonce(
 async fn register_key(
    db: &DatabasePool,
    keyholder: &ActorRef<KeyHolder>,
-    pubkey: &authn::PublicKey,
+    pubkey: &AuthPublicKey,
 ) -> Result<(), 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 pubkey_bytes = pubkey.to_stored_bytes();
+    let key_type = pubkey.key_type();
+    let mut conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;

    conn.transaction(|conn| {
        Box::pin(async move {
@@ -169,26 +167,37 @@ async fn register_key(
                .values((
                    useragent_client::public_key.eq(pubkey_bytes),
                    useragent_client::nonce.eq(NONCE_START),
+                    useragent_client::key_type.eq(key_type),
                ))
                .returning(useragent_client::id)
                .get_result(conn)
                .await
-                .map_err(|e| {
-                    error!(error = ?e, "Database error");
-                    Error::internal("Database operation failed")
-                })?;
+                .map_err(|e| Error::internal("Database operation failed", &e))?;

-            let entity = UserAgentCredentials {
-                pubkey: pubkey.clone(),
-                nonce: NONCE_START,
-            };
-
-            integrity::sign_entity(conn, keyholder, &entity, id)
-                .await
-                .map_err(|e| {
-                    error!(error = ?e, "Failed to sign integrity tag for new user-agent key");
-                    Error::internal("Failed to register public key")
-                })?;
+            if let Err(e) = integrity::sign_entity(
+                conn,
+                keyholder,
+                &UserAgentCredentials {
+                    pubkey: pubkey.clone(),
+                    nonce: NONCE_START,
+                },
+                id,
+            )
+            .await
+            {
+                match e {
+                    integrity::Error::Keyholder(
+                        crate::actors::keyholder::Error::NotBootstrapped,
+                    ) => {
+                        // IMPORTANT: bootstrap-token auth must work before the vault has a root key.
+                        // We intentionally allow creating the DB row first and backfill envelopes
+                        // after bootstrap/unseal to keep the bootstrap flow possible.
+                    }
+                    other => {
+                        return Err(Error::internal("Failed to register public key", &other));
+                    }
+                }
+            }

            Result::<_, Error>::Ok(())
        })
@@ -242,7 +251,7 @@ where
    async fn verify_bootstrap_token(
        &mut self,
        BootstrapAuthRequest { pubkey, token }: BootstrapAuthRequest,
-    ) -> Result<authn::PublicKey, Self::Error> {
+    ) -> Result<AuthPublicKey, Self::Error> {
        let token_ok: bool = self
            .conn
            .actors
@@ -251,10 +260,7 @@ where
                token: token.clone(),
            })
            .await
-            .map_err(|e| {
-                error!(?e, "Failed to consume bootstrap token");
-                Error::internal("Failed to consume bootstrap token")
-            })?;
+            .map_err(|e| Error::internal("Failed to consume bootstrap token", &e))?;

        if !token_ok {
            error!("Invalid bootstrap token provided");
@@ -290,13 +296,35 @@ where
            key,
        }: &ChallengeContext,
        ChallengeSolution { solution }: ChallengeSolution,
-    ) -> Result<authn::PublicKey, Self::Error> {
-        let signature = authn::Signature::try_from(solution.as_slice()).map_err(|_| {
-            error!("Failed to decode signature in challenge solution");
-            Error::InvalidChallengeSolution
-        })?;
+    ) -> Result<AuthPublicKey, Self::Error> {
+        let formatted = arbiter_proto::format_challenge(*challenge_nonce, &key.to_stored_bytes());

-        let valid = key.verify(*challenge_nonce, USERAGENT_CONTEXT, &signature);
+        let valid = match key {
+            AuthPublicKey::Ed25519(vk) => {
+                let sig = solution.as_slice().try_into().map_err(|_| {
+                    error!(?solution, "Invalid Ed25519 signature length");
+                    Error::InvalidChallengeSolution
+                })?;
+                vk.verify_strict(&formatted, &sig).is_ok()
+            }
+            AuthPublicKey::EcdsaSecp256k1(vk) => {
+                use k256::ecdsa::signature::Verifier as _;
+                let sig = k256::ecdsa::Signature::try_from(solution.as_slice()).map_err(|_| {
+                    error!(?solution, "Invalid ECDSA signature bytes");
+                    Error::InvalidChallengeSolution
+                })?;
+                vk.verify(&formatted, &sig).is_ok()
+            }
+            AuthPublicKey::Rsa(pk) => {
+                use rsa::signature::Verifier as _;
+                let verifying_key = rsa::pss::VerifyingKey::<sha2::Sha256>::new(pk.clone());
+                let sig = rsa::pss::Signature::try_from(solution.as_slice()).map_err(|_| {
+                    error!(?solution, "Invalid RSA signature bytes");
+                    Error::InvalidChallengeSolution
+                })?;
+                verifying_key.verify(&formatted, &sig).is_ok()
+            }
+        };

        match valid {
            true => {
--- a/server/crates/arbiter-server/src/actors/user_agent/mod.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/mod.rs
@@ -1,13 +1,22 @@
 use crate::{
    actors::{GlobalActors, client::ClientProfile},
    crypto::integrity::Integrable,
-    db,
+    db::{self, models::KeyType},
 };
-use arbiter_crypto::authn;

-#[derive(Debug, arbiter_macros::Hashable)]
+/// Abstraction over Ed25519 / ECDSA-secp256k1 / RSA public keys used during the auth handshake.
+#[derive(Clone, Debug)]
+pub enum AuthPublicKey {
+    Ed25519(ed25519_dalek::VerifyingKey),
+    /// Compressed SEC1 public key; signature bytes are raw 64-byte (r||s).
+    EcdsaSecp256k1(k256::ecdsa::VerifyingKey),
+    /// RSA-2048+ public key (Windows Hello / KeyCredentialManager); signature bytes are PSS+SHA-256.
+    Rsa(rsa::RsaPublicKey),
+}
+
+#[derive(Debug)]
 pub struct UserAgentCredentials {
-    pub pubkey: authn::PublicKey,
+    pub pubkey: AuthPublicKey,
    pub nonce: i32,
 }

@@ -15,11 +24,67 @@ impl Integrable for UserAgentCredentials {
    const KIND: &'static str = "useragent_credentials";
 }

+impl AuthPublicKey {
+    /// Canonical bytes stored in DB and echoed back in the challenge.
+    /// Ed25519: raw 32 bytes. ECDSA: SEC1 compressed 33 bytes. RSA: DER-encoded SPKI.
+    pub fn to_stored_bytes(&self) -> Vec<u8> {
+        match self {
+            AuthPublicKey::Ed25519(k) => k.to_bytes().to_vec(),
+            // SEC1 compressed (33 bytes) is the natural compact format for secp256k1
+            AuthPublicKey::EcdsaSecp256k1(k) => k.to_encoded_point(true).as_bytes().to_vec(),
+            AuthPublicKey::Rsa(k) => {
+                use rsa::pkcs8::EncodePublicKey as _;
+                #[allow(clippy::expect_used)]
+                k.to_public_key_der()
+                    .expect("rsa SPKI encoding is infallible")
+                    .to_vec()
+            }
+        }
+    }
+
+    pub fn key_type(&self) -> KeyType {
+        match self {
+            AuthPublicKey::Ed25519(_) => KeyType::Ed25519,
+            AuthPublicKey::EcdsaSecp256k1(_) => KeyType::EcdsaSecp256k1,
+            AuthPublicKey::Rsa(_) => KeyType::Rsa,
+        }
+    }
+}
+
+impl TryFrom<(KeyType, Vec<u8>)> for AuthPublicKey {
+    type Error = &'static str;
+
+    fn try_from(value: (KeyType, Vec<u8>)) -> Result<Self, Self::Error> {
+        let (key_type, bytes) = value;
+        match key_type {
+            KeyType::Ed25519 => {
+                let bytes: [u8; 32] = bytes.try_into().map_err(|_| "invalid Ed25519 key length")?;
+                let key = ed25519_dalek::VerifyingKey::from_bytes(&bytes)
+                    .map_err(|_e| "invalid Ed25519 key")?;
+                Ok(AuthPublicKey::Ed25519(key))
+            }
+            KeyType::EcdsaSecp256k1 => {
+                let point =
+                    k256::EncodedPoint::from_bytes(&bytes).map_err(|_e| "invalid ECDSA key")?;
+                let key = k256::ecdsa::VerifyingKey::from_encoded_point(&point)
+                    .map_err(|_e| "invalid ECDSA key")?;
+                Ok(AuthPublicKey::EcdsaSecp256k1(key))
+            }
+            KeyType::Rsa => {
+                use rsa::pkcs8::DecodePublicKey as _;
+                let key = rsa::RsaPublicKey::from_public_key_der(&bytes)
+                    .map_err(|_e| "invalid RSA key")?;
+                Ok(AuthPublicKey::Rsa(key))
+            }
+        }
+    }
+}
+
 // Messages, sent by user agent to connection client without having a request
 #[derive(Debug)]
 pub enum OutOfBand {
    ClientConnectionRequest { profile: ClientProfile },
-    ClientConnectionCancel { pubkey: authn::PublicKey },
+    ClientConnectionCancel { pubkey: ed25519_dalek::VerifyingKey },
 }

 pub struct UserAgentConnection {
@@ -38,3 +103,18 @@ pub mod session;

 pub use auth::authenticate;
 pub use session::UserAgentSession;
+
+use crate::crypto::integrity::hashing::Hashable;
+
+impl Hashable for AuthPublicKey {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        hasher.update(self.to_stored_bytes());
+    }
+}
+
+impl Hashable for UserAgentCredentials {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        self.pubkey.hash(hasher);
+        self.nonce.hash(hasher);
+    }
+}
--- a/server/crates/arbiter-server/src/actors/user_agent/session.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/session.rs
@@ -1,9 +1,8 @@
-use arbiter_crypto::authn;
-
 use std::{borrow::Cow, collections::HashMap};

 use arbiter_proto::transport::Sender;
 use async_trait::async_trait;
+use ed25519_dalek::VerifyingKey;
 use kameo::{Actor, actor::ActorRef, messages};
 use thiserror::Error;
 use tracing::error;
@@ -13,6 +12,7 @@ use crate::actors::{
    flow_coordinator::{RegisterUserAgent, client_connect_approval::ClientApprovalController},
    user_agent::{OutOfBand, UserAgentConnection},
 };
+
 mod state;
 use state::{DummyContext, UserAgentEvents, UserAgentStateMachine};

@@ -47,7 +47,6 @@ impl Error {
 }

 pub struct PendingClientApproval {
-    pubkey: authn::PublicKey,
    controller: ActorRef<ClientApprovalController>,
 }

@@ -56,7 +55,7 @@ pub struct UserAgentSession {
    state: UserAgentStateMachine<DummyContext>,
    sender: Box<dyn Sender<OutOfBand>>,

-    pending_client_approvals: HashMap<Vec<u8>, PendingClientApproval>,
+    pending_client_approvals: HashMap<VerifyingKey, PendingClientApproval>,
 }

 pub mod connection;
@@ -119,13 +118,8 @@ impl UserAgentSession {
            return;
        }

-        self.pending_client_approvals.insert(
-            client.pubkey.to_bytes(),
-            PendingClientApproval {
-                pubkey: client.pubkey,
-                controller,
-            },
-        );
+        self.pending_client_approvals
+            .insert(client.pubkey, PendingClientApproval { controller });
    }
 }

@@ -164,18 +158,14 @@ impl Actor for UserAgentSession {
        let cancelled_pubkey = self
            .pending_client_approvals
            .iter()
-            .find_map(|(k, v)| (v.controller.id() == id).then_some(k.clone()));
+            .find_map(|(k, v)| (v.controller.id() == id).then_some(*k));

-        if let Some(pubkey_bytes) = cancelled_pubkey {
-            let Some(approval) = self.pending_client_approvals.remove(&pubkey_bytes) else {
-                return Ok(std::ops::ControlFlow::Continue(()));
-            };
+        if let Some(pubkey) = cancelled_pubkey {
+            self.pending_client_approvals.remove(&pubkey);

            if let Err(e) = self
                .sender
-                .send(OutOfBand::ClientConnectionCancel {
-                    pubkey: approval.pubkey,
-                })
+                .send(OutOfBand::ClientConnectionCancel { pubkey })
                .await
            {
                error!(
--- a/server/crates/arbiter-server/src/actors/user_agent/session/connection.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/session/connection.rs
@@ -1,10 +1,6 @@
 use std::sync::Mutex;

 use alloy::{consensus::TxEip1559, primitives::Address, signers::Signature};
-use arbiter_crypto::{
-    authn,
-    safecell::{SafeCell, SafeCellHandle as _},
-};
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
 use diesel::{ExpressionMethods as _, QueryDsl as _, SelectableHelper};
 use diesel_async::{AsyncConnection, RunQueryDsl};
@@ -14,26 +10,88 @@ use kameo::prelude::Context;
 use tracing::{error, info};
 use x25519_dalek::{EphemeralSecret, PublicKey};

-use crate::actors::flow_coordinator::client_connect_approval::ClientApprovalAnswer;
 use crate::actors::keyholder::KeyHolderState;
 use crate::actors::user_agent::session::Error;
-use crate::actors::{
-    evm::{
-        ClientSignTransaction, Generate, ListWallets, SignTransactionError as EvmSignError,
-        UseragentCreateGrant, UseragentListGrants,
-    },
-    keyholder::{self, Bootstrap, TryUnseal},
-    user_agent::session::{
-        UserAgentSession,
-        state::{UnsealContext, UserAgentEvents, UserAgentStates},
-    },
-};
 use crate::db::models::{
    EvmWalletAccess, NewEvmWalletAccess, ProgramClient, ProgramClientMetadata,
 };
 use crate::evm::policies::{Grant, SpecificGrant};
+use crate::safe_cell::SafeCell;
+use crate::{
+    actors::flow_coordinator::client_connect_approval::ClientApprovalAnswer,
+    crypto::integrity::{self, Verified},
+};
+use crate::{
+    actors::{
+        evm::{
+            ClientSignTransaction, Generate, ListWallets, SignTransactionError as EvmSignError,
+            UseragentCreateGrant, UseragentDeleteGrant, UseragentListGrants,
+        },
+        keyholder::{self, Bootstrap, TryUnseal},
+        user_agent::session::{
+            UserAgentSession,
+            state::{UnsealContext, UserAgentEvents, UserAgentStates},
+        },
+        user_agent::{AuthPublicKey, UserAgentCredentials},
+    },
+    db::schema::useragent_client,
+    safe_cell::SafeCellHandle as _,
+};
+
+fn is_vault_sealed_from_evm<M>(err: &SendError<M, crate::actors::evm::Error>) -> bool {
+    matches!(
+        err,
+        SendError::HandlerError(crate::actors::evm::Error::Keyholder(
+            keyholder::Error::NotBootstrapped
+        )) | SendError::HandlerError(crate::actors::evm::Error::Integrity(
+            crate::crypto::integrity::Error::Keyholder(keyholder::Error::NotBootstrapped)
+        ))
+    )
+}

 impl UserAgentSession {
+    async fn backfill_useragent_integrity(&self) -> Result<(), Error> {
+        let mut conn = self.props.db.get().await?;
+        let keyholder = self.props.actors.key_holder.clone();
+
+        conn.transaction(|conn| {
+            Box::pin(async move {
+                let rows: Vec<(i32, i32, Vec<u8>, crate::db::models::KeyType)> =
+                    useragent_client::table
+                        .select((
+                            useragent_client::id,
+                            useragent_client::nonce,
+                            useragent_client::public_key,
+                            useragent_client::key_type,
+                        ))
+                        .load(conn)
+                        .await?;
+
+                for (id, nonce, public_key, key_type) in rows {
+                    let pubkey = AuthPublicKey::try_from((key_type, public_key)).map_err(|e| {
+                        Error::internal(format!("Invalid user-agent key in db: {e}"))
+                    })?;
+
+                    integrity::sign_entity(
+                        conn,
+                        &keyholder,
+                        &UserAgentCredentials { pubkey, nonce },
+                        id,
+                    )
+                    .await
+                    .map_err(|e| {
+                        Error::internal(format!("Failed to backfill user-agent integrity: {e}"))
+                    })?;
+                }
+
+                Result::<_, Error>::Ok(())
+            })
+        })
+        .await?;
+
+        Ok(())
+    }
+
    fn take_unseal_secret(&mut self) -> Result<(EphemeralSecret, PublicKey), Error> {
        let UserAgentStates::WaitingForUnsealKey(unseal_context) = self.state.state() else {
            error!("Received encrypted key in invalid state");
@@ -191,6 +249,7 @@ impl UserAgentSession {
            .await
        {
            Ok(_) => {
+                self.backfill_useragent_integrity().await?;
                info!("Successfully unsealed key with client-provided key");
                self.transition(UserAgentEvents::ReceivedValidKey)?;
                Ok(())
@@ -252,6 +311,7 @@ impl UserAgentSession {
            .await
        {
            Ok(_) => {
+                self.backfill_useragent_integrity().await?;
                info!("Successfully bootstrapped vault with client-provided key");
                self.transition(UserAgentEvents::ReceivedValidKey)?;
                Ok(())
@@ -325,12 +385,15 @@ impl UserAgentSession {
 #[messages]
 impl UserAgentSession {
    #[message]
-    pub(crate) async fn handle_grant_list(&mut self) -> Result<Vec<Grant<SpecificGrant>>, Error> {
+    pub(crate) async fn handle_grant_list(
+        &mut self,
+    ) -> Result<Vec<Grant<SpecificGrant>>, GrantMutationError> {
        match self.props.actors.evm.ask(UseragentListGrants {}).await {
            Ok(grants) => Ok(grants),
+            Err(err) if is_vault_sealed_from_evm(&err) => Err(GrantMutationError::VaultSealed),
            Err(err) => {
                error!(?err, "EVM grant list failed");
-                Err(Error::internal("Failed to list EVM grants"))
+                Err(GrantMutationError::Internal)
            }
        }
    }
@@ -340,7 +403,7 @@ impl UserAgentSession {
        &mut self,
        basic: crate::evm::policies::SharedGrantSettings,
        grant: crate::evm::policies::SpecificGrant,
-    ) -> Result<i32, GrantMutationError> {
+    ) -> Result<Verified<i32>, GrantMutationError> {
        match self
            .props
            .actors
@@ -349,6 +412,7 @@ impl UserAgentSession {
            .await
        {
            Ok(grant_id) => Ok(grant_id),
+            Err(err) if is_vault_sealed_from_evm(&err) => Err(GrantMutationError::VaultSealed),
            Err(err) => {
                error!(?err, "EVM grant create failed");
                Err(GrantMutationError::Internal)
@@ -361,21 +425,22 @@ impl UserAgentSession {
        &mut self,
        grant_id: i32,
    ) -> Result<(), GrantMutationError> {
-        // match self
-        //     .props
-        //     .actors
-        //     .evm
-        //     .ask(UseragentDeleteGrant { grant_id })
-        //     .await
-        // {
-        //     Ok(()) => Ok(()),
-        //     Err(err) => {
-        //         error!(?err, "EVM grant delete failed");
-        //         Err(GrantMutationError::Internal)
-        //     }
-        // }
-       let _ = grant_id;
-        todo!()
+        match self
+            .props
+            .actors
+            .evm
+            .ask(UseragentDeleteGrant {
+                _grant_id: grant_id,
+            })
+            .await
+        {
+            Ok(()) => Ok(()),
+            Err(err) if is_vault_sealed_from_evm(&err) => Err(GrantMutationError::VaultSealed),
+            Err(err) => {
+                error!(?err, "EVM grant delete failed");
+                Err(GrantMutationError::Internal)
+            }
+        }
    }

    #[message]
@@ -475,10 +540,10 @@ impl UserAgentSession {
    pub(crate) async fn handle_new_client_approve(
        &mut self,
        approved: bool,
-        pubkey: authn::PublicKey,
+        pubkey: ed25519_dalek::VerifyingKey,
        ctx: &mut Context<Self, Result<(), Error>>,
    ) -> Result<(), Error> {
-        let pending_approval = match self.pending_client_approvals.remove(&pubkey.to_bytes()) {
+        let pending_approval = match self.pending_client_approvals.remove(&pubkey) {
            Some(approval) => approval,
            None => {
                error!("Received client connection response for unknown client");
--- a/server/crates/arbiter-server/src/crypto/encryption/v1.rs
+++ b/server/crates/arbiter-server/src/crypto/encryption/v1.rs
@@ -59,8 +59,10 @@ mod tests {
    use std::ops::Deref as _;

    use super::*;
-    use crate::crypto::derive_key;
-    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+    use crate::{
+        crypto::derive_key,
+        safe_cell::{SafeCell, SafeCellHandle as _},
+    };

    #[test]
    pub fn derive_seal_key_deterministic() {
--- a/server/crates/arbiter-server/src/crypto/integrity/v1.rs
+++ b/server/crates/arbiter-server/src/crypto/integrity/v1.rs
@@ -1,18 +1,23 @@
 use crate::actors::keyholder;
-use arbiter_crypto::hashing::Hashable;
 use hmac::Hmac;
 use sha2::Sha256;
+use std::future::Future;
+use std::ops::Deref;
+use std::pin::Pin;

 use diesel::{ExpressionMethods as _, QueryDsl, dsl::insert_into, sqlite::Sqlite};
 use diesel_async::{AsyncConnection, RunQueryDsl};
 use kameo::{actor::ActorRef, error::SendError};
 use sha2::Digest as _;

+pub mod hashing;
+use self::hashing::Hashable;
+
 use crate::{
    actors::keyholder::{KeyHolder, SignIntegrity, VerifyIntegrity},
    db::{
        self,
-        models::{IntegrityEnvelope, NewIntegrityEnvelope},
+        models::{IntegrityEnvelope as IntegrityEnvelopeRow, NewIntegrityEnvelope},
        schema::integrity_envelope,
    },
 };
@@ -45,11 +50,35 @@ pub enum Error {
 }

 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[must_use]
 pub enum AttestationStatus {
    Attested,
    Unavailable,
 }

+#[derive(Debug)]
+pub struct Verified<T>(T);
+
+impl<T> AsRef<T> for Verified<T> {
+    fn as_ref(&self) -> &T {
+        &self.0
+    }
+}
+
+impl<T> Verified<T> {
+    pub fn into_inner(self) -> T {
+        self.0
+    }
+}
+
+impl<T> Deref for Verified<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
 pub const CURRENT_PAYLOAD_VERSION: i32 = 1;
 pub const INTEGRITY_SUBKEY_TAG: &[u8] = b"arbiter/db-integrity-key/v1";

@@ -85,31 +114,95 @@ fn build_mac_input(
    out
 }

-pub trait IntoId {
-    fn into_id(self) -> Vec<u8>;
-}
+#[derive(Debug, Clone)]
+pub struct EntityId(Vec<u8>);

-impl IntoId for i32 {
-    fn into_id(self) -> Vec<u8> {
-        self.to_be_bytes().to_vec()
+impl Deref for EntityId {
+    type Target = [u8];
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
    }
 }

-impl IntoId for &'_ [u8] {
-    fn into_id(self) -> Vec<u8> {
-        self.to_vec()
+impl From<i32> for EntityId {
+    fn from(value: i32) -> Self {
+        Self(value.to_be_bytes().to_vec())
    }
 }

-pub async fn sign_entity<E: Integrable>(
+impl From<&'_ [u8]> for EntityId {
+    fn from(bytes: &'_ [u8]) -> Self {
+        Self(bytes.to_vec())
+    }
+}
+
+pub async fn lookup_verified<E, C, F, Fut>(
+    conn: &mut C,
+    keyholder: &ActorRef<KeyHolder>,
+    entity_id: impl Into<EntityId>,
+    load: F,
+) -> Result<Verified<E>, Error>
+where
+    C: AsyncConnection<Backend = Sqlite>,
+    E: Integrable,
+    F: FnOnce(&mut C) -> Fut,
+    Fut: Future<Output = Result<E, db::DatabaseError>>,
+{
+    let entity = load(conn).await?;
+    verify_entity(conn, keyholder, &entity, entity_id).await?;
+    Ok(Verified(entity))
+}
+
+pub async fn lookup_verified_allow_unavailable<E, C, F, Fut>(
+    conn: &mut C,
+    keyholder: &ActorRef<KeyHolder>,
+    entity_id: impl Into<EntityId>,
+    load: F,
+) -> Result<Verified<E>, Error>
+where
+    C: AsyncConnection<Backend = Sqlite>,
+    E: Integrable+ 'static,
+    F: FnOnce(&mut C) -> Fut,
+    Fut: Future<Output = Result<E, db::DatabaseError>>,
+{
+    let entity = load(conn).await?;
+    match check_entity_attestation(conn, keyholder, &entity, entity_id.into()).await? {
+        // IMPORTANT: allow_unavailable mode must succeed with an unattested result when vault key
+        // material is unavailable, otherwise integrity checks can be silently bypassed while sealed.
+        AttestationStatus::Attested | AttestationStatus::Unavailable => Ok(Verified(entity)),
+    }
+}
+
+pub async fn lookup_verified_from_query<E, Id, C, F>(
+    conn: &mut C,
+    keyholder: &ActorRef<KeyHolder>,
+    load: F,
+) -> Result<Verified<E>, Error>
+where
+    C: AsyncConnection<Backend = Sqlite> + Send,
+    E: Integrable,
+    Id: Into<EntityId>,
+    F: for<'a> FnOnce(
+        &'a mut C,
+    ) -> Pin<
+        Box<dyn Future<Output = Result<(Id, E), db::DatabaseError>> + Send + 'a>,
+    >,
+{
+    let (entity_id, entity) = load(conn).await?;
+    verify_entity(conn, keyholder, &entity, entity_id).await?;
+    Ok(Verified(entity))
+}
+
+pub async fn sign_entity<E: Integrable, Id: Into<EntityId> + Clone>(
    conn: &mut impl AsyncConnection<Backend = Sqlite>,
    keyholder: &ActorRef<KeyHolder>,
    entity: &E,
-    entity_id: impl IntoId,
-) -> Result<(), Error> {
-    let payload_hash = payload_hash(&entity);
+    as_entity_id: Id,
+) -> Result<Verified<Id>, Error> {
+    let payload_hash = payload_hash(entity);

-    let entity_id = entity_id.into_id();
+    let entity_id = as_entity_id.clone().into();

    let mac_input = build_mac_input(E::KIND, &entity_id, E::VERSION, &payload_hash);

@@ -124,7 +217,7 @@ pub async fn sign_entity<E: Integrable>(
    insert_into(integrity_envelope::table)
        .values(NewIntegrityEnvelope {
            entity_kind: E::KIND.to_owned(),
-            entity_id,
+            entity_id: entity_id.to_vec(),
            payload_version: E::VERSION,
            key_version,
            mac: mac.to_vec(),
@@ -143,19 +236,19 @@ pub async fn sign_entity<E: Integrable>(
        .await
        .map_err(db::DatabaseError::from)?;

-    Ok(())
+    Ok(Verified(as_entity_id))
 }

-pub async fn verify_entity<E: Integrable>(
+pub async fn check_entity_attestation<E: Integrable>(
    conn: &mut impl AsyncConnection<Backend = Sqlite>,
    keyholder: &ActorRef<KeyHolder>,
    entity: &E,
-    entity_id: impl IntoId,
+    entity_id: impl Into<EntityId>,
 ) -> Result<AttestationStatus, Error> {
-    let entity_id = entity_id.into_id();
-    let envelope: IntegrityEnvelope = integrity_envelope::table
+    let entity_id = entity_id.into();
+    let envelope: IntegrityEnvelopeRow = integrity_envelope::table
        .filter(integrity_envelope::entity_kind.eq(E::KIND))
-        .filter(integrity_envelope::entity_id.eq(&entity_id))
+        .filter(integrity_envelope::entity_id.eq(&*entity_id))
        .first(conn)
        .await
        .map_err(|err| match err {
@@ -173,7 +266,7 @@ pub async fn verify_entity<E: Integrable>(
        });
    }

-    let payload_hash = payload_hash(&entity);
+    let payload_hash = payload_hash(entity);
    let mac_input = build_mac_input(E::KIND, &entity_id, envelope.payload_version, &payload_hash);

    let result = keyholder
@@ -196,24 +289,67 @@ pub async fn verify_entity<E: Integrable>(
    }
 }

+pub async fn verify_entity<'a, E: Integrable>(
+    conn: &mut impl AsyncConnection<Backend = Sqlite>,
+    keyholder: &ActorRef<KeyHolder>,
+    entity: &'a E,
+    entity_id: impl Into<EntityId>,
+) -> Result<Verified<&'a E>, Error> {
+    match check_entity_attestation::<E>(conn, keyholder, entity, entity_id).await? {
+        AttestationStatus::Attested => Ok(Verified(entity)),
+        AttestationStatus::Unavailable => Err(Error::Keyholder(keyholder::Error::NotBootstrapped)),
+    }
+}
+
+pub async fn delete_envelope<E: Integrable>(
+    conn: &mut impl AsyncConnection<Backend = Sqlite>,
+    entity_id: impl Into<EntityId>,
+) -> Result<usize, Error> {
+    let entity_id = entity_id.into();
+
+    let affected = diesel::delete(
+        integrity_envelope::table
+            .filter(integrity_envelope::entity_kind.eq(E::KIND))
+            .filter(integrity_envelope::entity_id.eq(&*entity_id)),
+    )
+    .execute(conn)
+    .await
+    .map_err(db::DatabaseError::from)?;
+
+    Ok(affected)
+}
+
 #[cfg(test)]
 mod tests {
    use diesel::{ExpressionMethods as _, QueryDsl};
    use diesel_async::RunQueryDsl;
    use kameo::{actor::ActorRef, prelude::Spawn};
+    use sha2::Digest;

    use crate::{
        actors::keyholder::{Bootstrap, KeyHolder},
        db::{self, schema},
+        safe_cell::{SafeCell, SafeCellHandle as _},
    };
-    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};

-    use super::{Error, Integrable, sign_entity, verify_entity};
-    #[derive(Clone, arbiter_macros::Hashable)]
+    use super::hashing::Hashable;
+    use super::{
+        check_entity_attestation, AttestationStatus, Error, Integrable, lookup_verified,
+        lookup_verified_allow_unavailable, lookup_verified_from_query, sign_entity, verify_entity,
+    };
+
+    #[derive(Clone, Debug)]
    struct DummyEntity {
        payload_version: i32,
        payload: Vec<u8>,
    }
+
+    impl Hashable for DummyEntity {
+        fn hash<H: Digest>(&self, hasher: &mut H) {
+            self.payload_version.hash(hasher);
+            self.payload.hash(hasher);
+        }
+    }
    impl Integrable for DummyEntity {
        const KIND: &'static str = "dummy_entity";
    }
@@ -255,7 +391,7 @@ mod tests {
            .unwrap();

        assert_eq!(count, 1, "envelope row must be created exactly once");
-        verify_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        let _ = check_entity_attestation(&mut conn, &keyholder, &entity, ENTITY_ID)
            .await
            .unwrap();
    }
@@ -285,7 +421,7 @@ mod tests {
            .await
            .unwrap();

-        let err = verify_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+        let err = check_entity_attestation(&mut conn, &keyholder, &entity, ENTITY_ID)
            .await
            .unwrap_err();
        assert!(matches!(err, Error::MacMismatch { .. }));
@@ -313,9 +449,233 @@ mod tests {
            ..entity
        };

-        let err = verify_entity(&mut conn, &keyholder, &tampered, ENTITY_ID)
+        let err = check_entity_attestation(&mut conn, &keyholder, &tampered, ENTITY_ID)
            .await
            .unwrap_err();
        assert!(matches!(err, Error::MacMismatch { .. }));
    }
+
+    #[tokio::test]
+    async fn allow_unavailable_lookup_passes_while_sealed() {
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        const ENTITY_ID: &[u8] = b"entity-id-31";
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+        drop(keyholder);
+
+        let sealed_keyholder = KeyHolder::spawn(KeyHolder::new(db.clone()).await.unwrap());
+        let status = check_entity_attestation(&mut conn, &sealed_keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+        assert_eq!(status, AttestationStatus::Unavailable);
+
+        #[expect(clippy::disallowed_methods, reason = "test only")]
+        lookup_verified_allow_unavailable(&mut conn, &sealed_keyholder, ENTITY_ID, |_| async {
+            Ok::<_, db::DatabaseError>(DummyEntity {
+                payload_version: 1,
+                payload: b"payload-v1".to_vec(),
+            })
+        })
+        .await
+        .unwrap();
+    }
+
+    #[tokio::test]
+    async fn strict_verify_fails_closed_while_sealed() {
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        const ENTITY_ID: &[u8] = b"entity-id-41";
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+        drop(keyholder);
+
+        let sealed_keyholder = KeyHolder::spawn(KeyHolder::new(db.clone()).await.unwrap());
+
+        let err = verify_entity(&mut conn, &sealed_keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap_err();
+        assert!(matches!(
+            err,
+            Error::Keyholder(crate::actors::keyholder::Error::NotBootstrapped)
+        ));
+
+        let err = lookup_verified(&mut conn, &sealed_keyholder, ENTITY_ID, |_| async {
+            Ok::<_, db::DatabaseError>(DummyEntity {
+                payload_version: 1,
+                payload: b"payload-v1".to_vec(),
+            })
+        })
+        .await
+        .unwrap_err();
+        assert!(matches!(
+            err,
+            Error::Keyholder(crate::actors::keyholder::Error::NotBootstrapped)
+        ));
+    }
+
+    #[tokio::test]
+    async fn lookup_verified_supports_loaded_aggregate() {
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        const ENTITY_ID: i32 = 77;
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+
+        let verified = lookup_verified(&mut conn, &keyholder, ENTITY_ID, |_| async {
+            Ok::<_, db::DatabaseError>(DummyEntity {
+                payload_version: 1,
+                payload: b"payload-v1".to_vec(),
+            })
+        })
+        .await
+        .unwrap();
+
+        assert_eq!(verified.payload, b"payload-v1".to_vec());
+    }
+
+    #[tokio::test]
+    async fn lookup_verified_allow_unavailable_works_while_sealed() {
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        const ENTITY_ID: i32 = 78;
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+        drop(keyholder);
+
+        let sealed_keyholder = KeyHolder::spawn(KeyHolder::new(db.clone()).await.unwrap());
+
+        #[expect(clippy::disallowed_methods, reason = "test only")]
+        lookup_verified_allow_unavailable(&mut conn, &sealed_keyholder, ENTITY_ID, |_| async {
+            Ok::<_, db::DatabaseError>(DummyEntity {
+                payload_version: 1,
+                payload: b"payload-v1".to_vec(),
+            })
+        })
+        .await
+        .unwrap();
+    }
+
+    #[tokio::test]
+    async fn extension_trait_lookup_verified_required_works() {
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        const ENTITY_ID: i32 = 79;
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+
+        let verified = lookup_verified(&mut conn, &keyholder, ENTITY_ID, |_| {
+            Box::pin(async {
+                Ok::<_, db::DatabaseError>(DummyEntity {
+                    payload_version: 1,
+                    payload: b"payload-v1".to_vec(),
+                })
+            })
+        })
+        .await
+        .unwrap();
+
+        assert_eq!(verified.payload, b"payload-v1".to_vec());
+    }
+
+    #[tokio::test]
+    async fn lookup_verified_from_query_helpers_work() {
+        let db = db::create_test_pool().await;
+        let keyholder = bootstrapped_keyholder(&db).await;
+        let mut conn = db.get().await.unwrap();
+
+        const ENTITY_ID: i32 = 80;
+
+        let entity = DummyEntity {
+            payload_version: 1,
+            payload: b"payload-v1".to_vec(),
+        };
+
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();
+
+        let verified = lookup_verified_from_query(&mut conn, &keyholder, |_| {
+            Box::pin(async {
+                Ok::<_, db::DatabaseError>((
+                    ENTITY_ID,
+                    DummyEntity {
+                        payload_version: 1,
+                        payload: b"payload-v1".to_vec(),
+                    },
+                ))
+            })
+        })
+        .await
+        .unwrap();
+
+        assert_eq!(verified.payload, b"payload-v1".to_vec());
+
+        drop(keyholder);
+        let sealed_keyholder = KeyHolder::spawn(KeyHolder::new(db.clone()).await.unwrap());
+
+        let err = lookup_verified_from_query(&mut conn, &sealed_keyholder, |_| {
+            Box::pin(async {
+                Ok::<_, db::DatabaseError>((
+                    ENTITY_ID,
+                    DummyEntity {
+                        payload_version: 1,
+                        payload: b"payload-v1".to_vec(),
+                    },
+                ))
+            })
+        })
+        .await
+        .unwrap_err();
+
+        assert!(matches!(
+            err,
+            Error::Keyholder(crate::actors::keyholder::Error::NotBootstrapped)
+        ));
+    }
 }
--- a/server/crates/arbiter-server/src/crypto/integrity/v1/hashing.rs
+++ b/server/crates/arbiter-server/src/crypto/integrity/v1/hashing.rs
@@ -1,25 +1,21 @@
-pub use hmac::digest::Digest;
+use hmac::digest::Digest;
 use std::collections::HashSet;

 /// Deterministically hash a value by feeding its fields into the hasher in a consistent order.
-#[diagnostic::on_unimplemented(
-    note = "for local types consider adding `#[derive(arbiter_macros::Hashable)]` to your `{Self}` type",
-    note = "for types from other crates check whether the crate offers a `Hashable` implementation"
-)]
 pub trait Hashable {
    fn hash<H: Digest>(&self, hasher: &mut H);
 }

 macro_rules! impl_numeric {
-    ($($t:ty),*) => {
-        $(
-            impl Hashable for $t {
-                fn hash<H: Digest>(&self, hasher: &mut H) {
-                    hasher.update(&self.to_be_bytes());
-                }
+($($t:ty),*) => {
+    $(
+        impl Hashable for $t {
+            fn hash<H: Digest>(&self, hasher: &mut H) {
+                hasher.update(&self.to_be_bytes());
            }
-        )*
-    };
+        }
+    )*
+};
 }

 impl_numeric!(u8, u16, u32, u64, i8, i16, i32, i64);
--- a/server/crates/arbiter-server/src/crypto/mod.rs
+++ b/server/crates/arbiter-server/src/crypto/mod.rs
@@ -10,7 +10,7 @@ use rand::{
    rngs::{StdRng, SysRng},
 };

-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+use crate::safe_cell::{SafeCell, SafeCellHandle as _};

 pub mod encryption;
 pub mod integrity;
@@ -141,7 +141,7 @@ mod tests {
        derive_key,
        encryption::v1::{Nonce, generate_salt},
    };
-    use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
+    use crate::safe_cell::{SafeCell, SafeCellHandle as _};

    #[test]
    pub fn encrypt_decrypt() {
--- a/server/crates/arbiter-server/src/db/models.rs
+++ b/server/crates/arbiter-server/src/db/models.rs
@@ -72,6 +72,40 @@ pub mod types {
            Ok(SqliteTimestamp(datetime))
        }
    }
+
+    /// Key algorithm stored in the `useragent_client.key_type` column.
+    /// Values must stay stable — they are persisted in the database.
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, FromSqlRow, AsExpression, strum::FromRepr)]
+    #[diesel(sql_type = Integer)]
+    #[repr(i32)]
+    pub enum KeyType {
+        Ed25519 = 1,
+        EcdsaSecp256k1 = 2,
+        Rsa = 3,
+    }
+
+    impl ToSql<Integer, Sqlite> for KeyType {
+        fn to_sql<'b>(
+            &'b self,
+            out: &mut diesel::serialize::Output<'b, '_, Sqlite>,
+        ) -> diesel::serialize::Result {
+            out.set_value(*self as i32);
+            Ok(IsNull::No)
+        }
+    }
+
+    impl FromSql<Integer, Sqlite> for KeyType {
+        fn from_sql(
+            mut bytes: <Sqlite as diesel::backend::Backend>::RawValue<'_>,
+        ) -> diesel::deserialize::Result<Self> {
+            let Some(SqliteType::Long) = bytes.value_type() else {
+                return Err("Expected Integer for KeyType".into());
+            };
+            let discriminant = bytes.read_long();
+            KeyType::from_repr(discriminant as i32)
+                .ok_or_else(|| format!("Unknown KeyType discriminant: {discriminant}").into())
+        }
+    }
 }
 pub use types::*;

@@ -210,6 +244,7 @@ pub struct UseragentClient {
    pub public_key: Vec<u8>,
    pub created_at: SqliteTimestamp,
    pub updated_at: SqliteTimestamp,
+    pub key_type: KeyType,
 }

 #[derive(Models, Queryable, Debug, Insertable, Selectable)]
--- a/server/crates/arbiter-server/src/evm/mod.rs
+++ b/server/crates/arbiter-server/src/evm/mod.rs
@@ -12,7 +12,7 @@ use kameo::actor::ActorRef;

 use crate::{
    actors::keyholder::KeyHolder,
-    crypto::integrity,
+    crypto::integrity::{self, Verified},
    db::{
        self, DatabaseError,
        models::{
@@ -153,12 +153,36 @@ impl Engine {
    {
        let mut conn = self.db.get().await.map_err(DatabaseError::from)?;

-        let grant = P::try_find_grant(&context, &mut conn)
+        let verified_settings =
+            match integrity::lookup_verified_from_query(&mut conn, &self.keyholder, |conn| {
+                let context = context.clone();
+                Box::pin(async move {
+                    let grant = P::try_find_grant(&context, conn)
+                        .await
+                        .map_err(DatabaseError::from)?
+                        .ok_or_else(|| DatabaseError::from(diesel::result::Error::NotFound))?;
+
+                    Ok::<_, DatabaseError>((grant.common_settings_id, grant.settings))
+                })
+            })
+            .await
+            {
+                Ok(verified) => verified,
+                Err(integrity::Error::Database(DatabaseError::Connection(
+                    diesel::result::Error::NotFound,
+                ))) => return Err(PolicyError::NoMatchingGrant),
+                Err(err) => return Err(PolicyError::Integrity(err)),
+            };
+
+        let mut grant = P::try_find_grant(&context, &mut conn)
            .await
            .map_err(DatabaseError::from)?
            .ok_or(PolicyError::NoMatchingGrant)?;

-        integrity::verify_entity(&mut conn, &self.keyholder, &grant.settings, grant.id).await?;
+        // IMPORTANT: policy evaluation uses extra non-integrity fields from Grant
+        // (e.g., per-policy ids), so we currently reload Grant after the query-native
+        // integrity check over canonicalized settings.
+        grant.settings = verified_settings.into_inner();

        let mut violations = check_shared_constraints(
            &context,
@@ -214,7 +238,7 @@ impl Engine {
    pub async fn create_grant<P: Policy>(
        &self,
        full_grant: CombinedSettings<P::Settings>,
-    ) -> Result<i32, DatabaseError>
+    ) -> Result<Verified<i32>, DatabaseError>
    where
        P::Settings: Clone,
    {
@@ -258,11 +282,12 @@ impl Engine {

                    P::create_grant(&basic_grant, &full_grant.specific, conn).await?;

-                    integrity::sign_entity(conn, &keyholder, &full_grant, basic_grant.id)
-                        .await
-                        .map_err(|_| diesel::result::Error::RollbackTransaction)?;
+                    let verified_entity_id =
+                        integrity::sign_entity(conn, &keyholder, &full_grant, basic_grant.id)
+                            .await
+                            .map_err(|_| diesel::result::Error::RollbackTransaction)?;

-                    QueryResult::Ok(basic_grant.id)
+                    QueryResult::Ok(verified_entity_id)
                })
            })
            .await?;
@@ -273,7 +298,7 @@ impl Engine {
    async fn list_one_kind<Kind: Policy, Y>(
        &self,
        conn: &mut impl AsyncConnection<Backend = Sqlite>,
-    ) -> Result<impl Iterator<Item = Grant<Y>>, ListError>
+    ) -> Result<Vec<Grant<Y>>, ListError>
    where
        Y: From<Kind::Settings>,
    {
@@ -281,16 +306,26 @@ impl Engine {
            .await
            .map_err(DatabaseError::from)?;

-        // Verify integrity of all grants before returning any results
-        for grant in &all_grants {
-            integrity::verify_entity(conn, &self.keyholder, &grant.settings, grant.id).await?;
+        let mut verified_grants = Vec::with_capacity(all_grants.len());
+
+        // Verify integrity of all grants before returning any results.
+        for grant in all_grants {
+            integrity::verify_entity(
+                conn,
+                &self.keyholder,
+                &grant.settings,
+                grant.common_settings_id,
+            )
+            .await?;
+
+            verified_grants.push(Grant {
+                id: grant.id,
+                common_settings_id: grant.common_settings_id,
+                settings: grant.settings.generalize(),
+            });
        }

-        Ok(all_grants.into_iter().map(|g| Grant {
-            id: g.id,
-            common_settings_id: g.common_settings_id,
-            settings: g.settings.generalize(),
-        }))
+        Ok(verified_grants)
    }

    pub async fn list_all_grants(&self) -> Result<Vec<Grant<SpecificGrant>>, ListError> {
@@ -394,7 +429,6 @@ 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,
@@ -597,24 +631,4 @@ mod tests {
            assert!(violations.is_empty());
        }
    }
-
-    #[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());
-    }
 }
--- a/server/crates/arbiter-server/src/evm/policies.rs
+++ b/server/crates/arbiter-server/src/evm/policies.rs
@@ -127,26 +127,25 @@ pub enum SpecificMeaning {
    TokenTransfer(token_transfers::Meaning),
 }

-#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, arbiter_macros::Hashable)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct TransactionRateLimit {
    pub count: u32,
    pub window: Duration,
 }

-#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, arbiter_macros::Hashable)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct VolumeRateLimit {
    pub max_volume: U256,
    pub window: Duration,
 }

-#[derive(Clone, Debug, PartialEq, Eq, Hash, arbiter_macros::Hashable)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct SharedGrantSettings {
    pub wallet_access_id: i32,
    pub chain: ChainId,

    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>,
@@ -161,7 +160,6 @@ impl SharedGrantSettings {
            chain: model.chain_id as u64, // safe because chain_id is stored as i32 but is guaranteed to be a valid ChainId by the API when creating grants
            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))
@@ -202,7 +200,7 @@ pub enum SpecificGrant {
    TokenTransfer(token_transfers::Settings),
 }

-#[derive(Debug, arbiter_macros::Hashable)]
+#[derive(Debug, Clone)]
 pub struct CombinedSettings<PolicyGrant> {
    pub shared: SharedGrantSettings,
    pub specific: PolicyGrant,
@@ -221,3 +219,38 @@ impl<P: Integrable> Integrable for CombinedSettings<P> {
    const KIND: &'static str = P::KIND;
    const VERSION: i32 = P::VERSION;
 }
+
+use crate::crypto::integrity::hashing::Hashable;
+
+impl Hashable for TransactionRateLimit {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        self.count.hash(hasher);
+        self.window.hash(hasher);
+    }
+}
+
+impl Hashable for VolumeRateLimit {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        self.max_volume.hash(hasher);
+        self.window.hash(hasher);
+    }
+}
+
+impl Hashable for SharedGrantSettings {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        self.wallet_access_id.hash(hasher);
+        self.chain.hash(hasher);
+        self.valid_from.hash(hasher);
+        self.valid_until.hash(hasher);
+        self.max_gas_fee_per_gas.hash(hasher);
+        self.max_priority_fee_per_gas.hash(hasher);
+        self.rate_limit.hash(hasher);
+    }
+}
+
+impl<P: Hashable> Hashable for CombinedSettings<P> {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        self.shared.hash(hasher);
+        self.specific.hash(hasher);
+    }
+}
--- a/server/crates/arbiter-server/src/evm/policies/ether_transfer/mod.rs
+++ b/server/crates/arbiter-server/src/evm/policies/ether_transfer/mod.rs
@@ -52,7 +52,7 @@ impl From<Meaning> for SpecificMeaning {
 }

 // A grant for ether transfers, which can be scoped to specific target addresses and volume limits
-#[derive(Debug, Clone, arbiter_macros::Hashable)]
+#[derive(Debug, Clone)]
 pub struct Settings {
    pub target: Vec<Address>,
    pub limit: VolumeRateLimit,
@@ -61,6 +61,15 @@ impl Integrable for Settings {
    const KIND: &'static str = "EtherTransfer";
 }

+use crate::crypto::integrity::hashing::Hashable;
+
+impl Hashable for Settings {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        self.target.hash(hasher);
+        self.limit.hash(hasher);
+    }
+}
+
 impl From<Settings> for SpecificGrant {
    fn from(val: Settings) -> SpecificGrant {
        SpecificGrant::EtherTransfer(val)
@@ -101,7 +110,8 @@ async fn check_rate_limits(
    let mut violations = Vec::new();
    let window = grant.settings.specific.limit.window;

-    let past_transaction = query_relevant_past_transaction(grant.id, window, db).await?;
+    let past_transaction =
+        query_relevant_past_transaction(grant.common_settings_id, window, db).await?;

    let window_start = chrono::Utc::now() - grant.settings.specific.limit.window;
    let prospective_cumulative_volume: U256 = past_transaction
@@ -240,21 +250,20 @@ impl Policy for EtherTransfer {
            })
            .collect();

-        let settings = 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 as i64),
-            },
-        };
-
        Ok(Some(Grant {
            id: grant.id,
            common_settings_id: grant.basic_grant_id,
            settings: CombinedSettings {
                shared: SharedGrantSettings::try_from_model(basic_grant)?,
-                specific: settings,
+                specific: 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 as i64),
+                    },
+                },
            },
        }))
    }
--- a/server/crates/arbiter-server/src/evm/policies/ether_transfer/tests.rs
+++ b/server/crates/arbiter-server/src/evm/policies/ether_transfer/tests.rs
@@ -78,7 +78,6 @@ 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,
@@ -341,7 +340,7 @@ proptest::proptest! {
    ) {
        use rand::{SeedableRng, seq::SliceRandom};
        use sha2::Digest;
-        use arbiter_crypto::hashing::Hashable;
+        use crate::crypto::integrity::hashing::Hashable;

        let addrs: Vec<Address> = raw_addrs.iter().map(|b| Address::from(*b)).collect();
        let mut shuffled = addrs.clone();
--- a/server/crates/arbiter-server/src/evm/policies/token_transfers/mod.rs
+++ b/server/crates/arbiter-server/src/evm/policies/token_transfers/mod.rs
@@ -62,7 +62,7 @@ impl From<Meaning> for SpecificMeaning {
 }

 // A grant for token transfers, which can be scoped to specific target addresses and volume limits
-#[derive(Debug, Clone, arbiter_macros::Hashable)]
+#[derive(Debug, Clone)]
 pub struct Settings {
    pub token_contract: Address,
    pub target: Option<Address>,
@@ -72,6 +72,16 @@ impl Integrable for Settings {
    const KIND: &'static str = "TokenTransfer";
 }

+use crate::crypto::integrity::hashing::Hashable;
+
+impl Hashable for Settings {
+    fn hash<H: sha2::Digest>(&self, hasher: &mut H) {
+        self.token_contract.hash(hasher);
+        self.target.hash(hasher);
+        self.volume_limits.hash(hasher);
+    }
+}
+
 impl From<Settings> for SpecificGrant {
    fn from(val: Settings) -> SpecificGrant {
        SpecificGrant::TokenTransfer(val)
@@ -276,18 +286,16 @@ impl Policy for TokenTransfer {
            }
        };

-        let settings = Settings {
-            token_contract: Address::from(token_contract),
-            target,
-            volume_limits,
-        };
-
        Ok(Some(Grant {
            id: token_grant.id,
            common_settings_id: token_grant.basic_grant_id,
            settings: CombinedSettings {
                shared: SharedGrantSettings::try_from_model(basic_grant)?,
-                specific: settings,
+                specific: Settings {
+                    token_contract: Address::from(token_contract),
+                    target,
+                    volume_limits,
+                },
            },
        }))
    }
--- a/server/crates/arbiter-server/src/evm/policies/token_transfers/tests.rs
+++ b/server/crates/arbiter-server/src/evm/policies/token_transfers/tests.rs
@@ -95,7 +95,6 @@ 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,
@@ -420,7 +419,7 @@ proptest::proptest! {
    ) {
        use rand::{SeedableRng, seq::SliceRandom};
        use sha2::Digest;
-        use arbiter_crypto::hashing::Hashable;
+        use crate::crypto::integrity::hashing::Hashable;

        let limits: Vec<VolumeRateLimit> = raw_limits
            .iter()
--- a/server/crates/arbiter-server/src/evm/safe_signer.rs
+++ b/server/crates/arbiter-server/src/evm/safe_signer.rs
@@ -1,12 +1,12 @@
 use std::sync::Mutex;

+use crate::safe_cell::{SafeCell, SafeCellHandle as _};
 use alloy::{
    consensus::SignableTransaction,
    network::{TxSigner, TxSignerSync},
    primitives::{Address, B256, ChainId, Signature},
    signers::{Error, Result, Signer, SignerSync, utils::secret_key_to_address},
 };
-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use async_trait::async_trait;
 use k256::ecdsa::{self, RecoveryId, SigningKey, signature::hazmat::PrehashSigner};

--- a/server/crates/arbiter-server/src/grpc/client/auth.rs
+++ b/server/crates/arbiter-server/src/grpc/client/auth.rs
@@ -1,4 +1,3 @@
-use arbiter_crypto::authn;
 use arbiter_proto::{
    ClientMetadata,
    proto::{
@@ -46,7 +45,7 @@ impl<'a> AuthTransportAdapter<'a> {
        match response {
            auth::Outbound::AuthChallenge { pubkey, nonce } => {
                AuthResponsePayload::Challenge(ProtoAuthChallenge {
-                    pubkey: pubkey.to_bytes(),
+                    pubkey: pubkey.to_bytes().to_vec(),
                    nonce,
                })
            }
@@ -161,7 +160,11 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
                        .await;
                    return None;
                };
-                let Ok(pubkey) = authn::PublicKey::try_from(pubkey.as_slice()) else {
+                let Ok(pubkey) = <[u8; 32]>::try_from(pubkey) else {
+                    let _ = self.send_auth_result(ProtoAuthResult::InvalidKey).await;
+                    return None;
+                };
+                let Ok(pubkey) = ed25519_dalek::VerifyingKey::from_bytes(&pubkey) else {
                    let _ = self.send_auth_result(ProtoAuthResult::InvalidKey).await;
                    return None;
                };
@@ -171,7 +174,7 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
                })
            }
            AuthRequestPayload::ChallengeSolution(ProtoAuthChallengeSolution { signature }) => {
-                let Ok(signature) = authn::Signature::try_from(signature.as_slice()) else {
+                let Ok(signature) = ed25519_dalek::Signature::try_from(signature.as_slice()) else {
                    let _ = self
                        .send_auth_result(ProtoAuthResult::InvalidSignature)
                        .await;
--- a/server/crates/arbiter-server/src/grpc/user_agent/auth.rs
+++ b/server/crates/arbiter-server/src/grpc/user_agent/auth.rs
@@ -1,4 +1,3 @@
-use arbiter_crypto::authn;
 use arbiter_proto::{
    proto::user_agent::{
        UserAgentRequest, UserAgentResponse,
@@ -6,7 +5,8 @@ use arbiter_proto::{
            self as proto_auth, AuthChallenge as ProtoAuthChallenge,
            AuthChallengeRequest as ProtoAuthChallengeRequest,
            AuthChallengeSolution as ProtoAuthChallengeSolution, AuthResult as ProtoAuthResult,
-            request::Payload as AuthRequestPayload, response::Payload as AuthResponsePayload,
+            KeyType as ProtoKeyType, request::Payload as AuthRequestPayload,
+            response::Payload as AuthResponsePayload,
        },
        user_agent_request::Payload as UserAgentRequestPayload,
        user_agent_response::Payload as UserAgentResponsePayload,
@@ -18,7 +18,8 @@ use tonic::Status;
 use tracing::warn;

 use crate::{
-    actors::user_agent::{UserAgentConnection, auth},
+    actors::user_agent::{AuthPublicKey, UserAgentConnection, auth},
+    db::models::KeyType,
    grpc::request_tracker::RequestTracker,
 };

@@ -140,9 +141,28 @@ impl Receiver<auth::Inbound> for AuthTransportAdapter<'_> {
            AuthRequestPayload::ChallengeRequest(ProtoAuthChallengeRequest {
                pubkey,
                bootstrap_token,
-                key_type: _,
+                key_type,
            }) => {
-                let Ok(pubkey) = authn::PublicKey::try_from(pubkey.as_slice()) else {
+                let Ok(key_type) = ProtoKeyType::try_from(key_type) else {
+                    warn!(
+                        event = "received request with invalid key type",
+                        "grpc.useragent.auth_adapter"
+                    );
+                    return None;
+                };
+                let key_type = match key_type {
+                    ProtoKeyType::Ed25519 => KeyType::Ed25519,
+                    ProtoKeyType::EcdsaSecp256k1 => KeyType::EcdsaSecp256k1,
+                    ProtoKeyType::Rsa => KeyType::Rsa,
+                    ProtoKeyType::Unspecified => {
+                        warn!(
+                            event = "received request with unspecified key type",
+                            "grpc.useragent.auth_adapter"
+                        );
+                        return None;
+                    }
+                };
+                let Ok(pubkey) = AuthPublicKey::try_from((key_type, pubkey)) else {
                    warn!(
                        event = "received request with invalid public key",
                        "grpc.useragent.auth_adapter"
@@ -168,7 +188,7 @@ pub async fn start(
    conn: &mut UserAgentConnection,
    bi: &mut GrpcBi<UserAgentRequest, UserAgentResponse>,
    request_tracker: &mut RequestTracker,
-) -> Result<authn::PublicKey, auth::Error> {
+) -> Result<AuthPublicKey, auth::Error> {
    let transport = AuthTransportAdapter::new(bi, request_tracker);
    auth::authenticate(conn, transport).await
 }
--- a/server/crates/arbiter-server/src/grpc/user_agent/evm.rs
+++ b/server/crates/arbiter-server/src/grpc/user_agent/evm.rs
@@ -121,6 +121,9 @@ async fn handle_grant_list(
                })
                .collect(),
        }),
+        Err(kameo::error::SendError::HandlerError(GrantMutationError::VaultSealed)) => {
+            EvmGrantListResult::Error(ProtoEvmError::VaultSealed.into())
+        }
        Err(err) => {
            warn!(error = ?err, "Failed to list EVM grants");
            EvmGrantListResult::Error(ProtoEvmError::Internal.into())
@@ -147,7 +150,7 @@ async fn handle_grant_create(
        .try_convert()?;

    let result = match actor.ask(HandleGrantCreate { basic, grant }).await {
-        Ok(grant_id) => EvmGrantCreateResult::GrantId(grant_id),
+        Ok(grant_id) => EvmGrantCreateResult::GrantId(grant_id.into_inner()),
        Err(kameo::error::SendError::HandlerError(GrantMutationError::VaultSealed)) => {
            EvmGrantCreateResult::Error(ProtoEvmError::VaultSealed.into())
        }
--- a/server/crates/arbiter-server/src/grpc/user_agent/inbound.rs
+++ b/server/crates/arbiter-server/src/grpc/user_agent/inbound.rs
@@ -87,7 +87,6 @@ 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()
--- a/server/crates/arbiter-server/src/grpc/user_agent/sdk_client.rs
+++ b/server/crates/arbiter-server/src/grpc/user_agent/sdk_client.rs
@@ -1,4 +1,3 @@
-use arbiter_crypto::authn;
 use arbiter_proto::proto::{
    shared::ClientInfo as ProtoClientMetadata,
    user_agent::{
@@ -42,7 +41,7 @@ pub(super) fn out_of_band_payload(oob: OutOfBand) -> UserAgentResponsePayload {
    match oob {
        OutOfBand::ClientConnectionRequest { profile } => wrap_sdk_client_response(
            SdkClientResponsePayload::ConnectionRequest(ProtoSdkClientConnectionRequest {
-                pubkey: profile.pubkey.to_bytes(),
+                pubkey: profile.pubkey.to_bytes().to_vec(),
                info: Some(ProtoClientMetadata {
                    name: profile.metadata.name,
                    description: profile.metadata.description,
@@ -52,7 +51,7 @@ pub(super) fn out_of_band_payload(oob: OutOfBand) -> UserAgentResponsePayload {
        ),
        OutOfBand::ClientConnectionCancel { pubkey } => wrap_sdk_client_response(
            SdkClientResponsePayload::ConnectionCancel(ProtoSdkClientConnectionCancel {
-                pubkey: pubkey.to_bytes(),
+                pubkey: pubkey.to_bytes().to_vec(),
            }),
        ),
    }
@@ -90,8 +89,10 @@ async fn handle_connection_response(
    actor: &ActorRef<UserAgentSession>,
    resp: ProtoSdkClientConnectionResponse,
 ) -> Result<Option<UserAgentResponsePayload>, Status> {
-    let pubkey = authn::PublicKey::try_from(resp.pubkey.as_slice())
-        .map_err(|_| Status::invalid_argument("Invalid ML-DSA public key"))?;
+    let pubkey_bytes = <[u8; 32]>::try_from(resp.pubkey)
+        .map_err(|_| Status::invalid_argument("Invalid Ed25519 public key length"))?;
+    let pubkey = ed25519_dalek::VerifyingKey::from_bytes(&pubkey_bytes)
+        .map_err(|_| Status::invalid_argument("Invalid Ed25519 public key"))?;

    actor
        .ask(HandleNewClientApprove {
@@ -116,7 +117,7 @@ async fn handle_list(
                .into_iter()
                .map(|(client, metadata)| ProtoSdkClientEntry {
                    id: client.id,
-                    pubkey: client.public_key.to_vec(),
+                    pubkey: client.public_key,
                    info: Some(ProtoClientMetadata {
                        name: metadata.name,
                        description: metadata.description,
--- a/server/crates/arbiter-server/src/lib.rs
+++ b/server/crates/arbiter-server/src/lib.rs
@@ -7,6 +7,7 @@ pub mod crypto;
 pub mod db;
 pub mod evm;
 pub mod grpc;
+pub mod safe_cell;
 pub mod utils;

 pub struct Server {
--- a/server/crates/arbiter-server/src/safe_cell.rs
+++ b/server/crates/arbiter-server/src/safe_cell.rs
@@ -105,11 +105,6 @@ impl<T> SafeCellHandle<T> for MemSafeCell<T> {

 fn abort_memory_breach(action: &str, err: &memsafe::error::MemoryError) -> ! {
    eprintln!("fatal {action}: {err}");
-    // SAFETY: Intentionally cause a segmentation fault to prevent further execution in a compromised state.
-    unsafe {
-        let unsafe_pointer = std::ptr::null_mut::<u8>();
-        std::ptr::write_volatile(unsafe_pointer, 0);
-    }
    std::process::abort();
 }

--- a/server/crates/arbiter-server/tests/client/auth.rs
+++ b/server/crates/arbiter-server/tests/client/auth.rs
@@ -1,7 +1,3 @@
-use arbiter_crypto::{
-    authn::{self, CLIENT_CONTEXT, format_challenge},
-    safecell::{SafeCell, SafeCellHandle as _},
-};
 use arbiter_proto::ClientMetadata;
 use arbiter_proto::transport::{Receiver, Sender};
 use arbiter_server::{
@@ -12,10 +8,11 @@ use arbiter_server::{
    },
    crypto::integrity,
    db::{self, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
 use diesel::{ExpressionMethods as _, NullableExpressionMethods as _, QueryDsl as _, insert_into};
 use diesel_async::RunQueryDsl;
-use ml_dsa::{KeyGen, MlDsa87, SigningKey, VerifyingKey, signature::Keypair as _};
+use ed25519_dalek::Signer as _;

 use super::common::ChannelTransport;

@@ -30,7 +27,7 @@ fn metadata(name: &str, description: Option<&str>, version: Option<&str>) -> Cli
 async fn insert_registered_client(
    db: &db::DatabasePool,
    actors: &GlobalActors,
-    pubkey: VerifyingKey<MlDsa87>,
+    pubkey: ed25519_dalek::VerifyingKey,
    metadata: &ClientMetadata,
 ) {
    use arbiter_server::db::schema::{client_metadata, program_client};
@@ -48,7 +45,7 @@ async fn insert_registered_client(
        .unwrap();
    let client_id: i32 = insert_into(program_client::table)
        .values((
-            program_client::public_key.eq(pubkey.encode().to_vec()),
+            program_client::public_key.eq(pubkey.to_bytes().to_vec()),
            program_client::metadata_id.eq(metadata_id),
        ))
        .returning(program_client::id)
@@ -59,33 +56,18 @@ async fn insert_registered_client(
    integrity::sign_entity(
        &mut conn,
        &actors.key_holder,
-        &ClientCredentials {
-            pubkey: pubkey.into(),
-            nonce: 1,
-        },
+        &ClientCredentials { pubkey, nonce: 1 },
        client_id,
    )
    .await
    .unwrap();
 }

-fn sign_client_challenge(
-    key: &SigningKey<MlDsa87>,
-    nonce: i32,
-    pubkey: &authn::PublicKey,
-) -> authn::Signature {
-    let challenge = format_challenge(nonce, &pubkey.to_bytes());
-    key.signing_key()
-        .sign_deterministic(&challenge, CLIENT_CONTEXT)
-        .unwrap()
-        .into()
-}
-
 async fn insert_bootstrap_sentinel_useragent(db: &db::DatabasePool) {
    let mut conn = db.get().await.unwrap();
-    let sentinel_key = MlDsa87::key_gen(&mut rand::rng())
+    let sentinel_key = ed25519_dalek::SigningKey::generate(&mut rand::rng())
        .verifying_key()
-        .encode()
+        .to_bytes()
        .to_vec();

    insert_into(schema::useragent_client::table)
@@ -125,11 +107,11 @@ pub async fn test_unregistered_pubkey_rejected() {
        connect_client(props, &mut server_transport).await;
    });

-    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());

    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: new_key.verifying_key(),
            metadata: metadata("client", Some("desc"), Some("1.0.0")),
        })
        .await
@@ -145,7 +127,7 @@ pub async fn test_challenge_auth() {
    let db = db::create_test_pool().await;
    let actors = spawn_test_actors(&db).await;

-    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());

    insert_registered_client(
        &db,
@@ -165,7 +147,7 @@ pub async fn test_challenge_auth() {
    // Send challenge request
    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: new_key.verifying_key(),
            metadata: metadata("client", Some("desc"), Some("1.0.0")),
        })
        .await
@@ -185,7 +167,8 @@ pub async fn test_challenge_auth() {
    };

    // Sign the challenge and send solution
-    let signature = sign_client_challenge(&new_key, challenge.1, &challenge.0);
+    let formatted_challenge = arbiter_proto::format_challenge(challenge.1, challenge.0.as_bytes());
+    let signature = new_key.sign(&formatted_challenge);

    test_transport
        .send(auth::Inbound::AuthChallengeSolution { signature })
@@ -211,7 +194,7 @@ pub async fn test_challenge_auth() {
 pub async fn test_metadata_unchanged_does_not_append_history() {
    let db = db::create_test_pool().await;
    let actors = spawn_test_actors(&db).await;
-    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    let requested = metadata("client", Some("desc"), Some("1.0.0"));

    insert_registered_client(&db, &actors, new_key.verifying_key(), &requested).await;
@@ -226,7 +209,7 @@ pub async fn test_metadata_unchanged_does_not_append_history() {

    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: new_key.verifying_key(),
            metadata: requested,
        })
        .await
@@ -237,7 +220,7 @@ pub async fn test_metadata_unchanged_does_not_append_history() {
        auth::Outbound::AuthChallenge { pubkey, nonce } => (pubkey, nonce),
        other => panic!("Expected AuthChallenge, got {other:?}"),
    };
-    let signature = sign_client_challenge(&new_key, nonce, &pubkey);
+    let signature = new_key.sign(&arbiter_proto::format_challenge(nonce, pubkey.as_bytes()));
    test_transport
        .send(auth::Inbound::AuthChallengeSolution { signature })
        .await
@@ -268,7 +251,7 @@ pub async fn test_metadata_unchanged_does_not_append_history() {
 pub async fn test_metadata_change_appends_history_and_repoints_binding() {
    let db = db::create_test_pool().await;
    let actors = spawn_test_actors(&db).await;
-    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());

    insert_registered_client(
        &db,
@@ -288,7 +271,7 @@ pub async fn test_metadata_change_appends_history_and_repoints_binding() {

    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: new_key.verifying_key(),
            metadata: metadata("client", Some("new"), Some("2.0.0")),
        })
        .await
@@ -299,7 +282,7 @@ pub async fn test_metadata_change_appends_history_and_repoints_binding() {
        auth::Outbound::AuthChallenge { pubkey, nonce } => (pubkey, nonce),
        other => panic!("Expected AuthChallenge, got {other:?}"),
    };
-    let signature = sign_client_challenge(&new_key, nonce, &pubkey);
+    let signature = new_key.sign(&arbiter_proto::format_challenge(nonce, pubkey.as_bytes()));
    test_transport
        .send(auth::Inbound::AuthChallengeSolution { signature })
        .await
@@ -356,7 +339,7 @@ pub async fn test_challenge_auth_rejects_integrity_tag_mismatch() {
    let db = db::create_test_pool().await;
    let actors = spawn_test_actors(&db).await;

-    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    let requested = metadata("client", Some("desc"), Some("1.0.0"));

    {
@@ -374,7 +357,7 @@ pub async fn test_challenge_auth_rejects_integrity_tag_mismatch() {
            .unwrap();
        insert_into(program_client::table)
            .values((
-                program_client::public_key.eq(new_key.verifying_key().encode().to_vec()),
+                program_client::public_key.eq(new_key.verifying_key().to_bytes().to_vec()),
                program_client::metadata_id.eq(metadata_id),
            ))
            .execute(&mut conn)
@@ -391,7 +374,7 @@ pub async fn test_challenge_auth_rejects_integrity_tag_mismatch() {

    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: new_key.verifying_key(),
            metadata: requested,
        })
        .await
--- a/server/crates/arbiter-server/tests/common/mod.rs
+++ b/server/crates/arbiter-server/tests/common/mod.rs
@@ -1,10 +1,9 @@
-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_proto::transport::{Bi, Error, Receiver, Sender};
 use arbiter_server::{
    actors::keyholder::KeyHolder,
    db::{self, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
-
 use async_trait::async_trait;
 use diesel::QueryDsl;
 use diesel_async::RunQueryDsl;
--- a/server/crates/arbiter-server/tests/keyholder/concurrency.rs
+++ b/server/crates/arbiter-server/tests/keyholder/concurrency.rs
@@ -1,11 +1,10 @@
 use std::collections::{HashMap, HashSet};

-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_server::{
    actors::keyholder::{CreateNew, Error, KeyHolder},
    db::{self, models, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
-
 use diesel::{ExpressionMethods as _, QueryDsl, SelectableHelper, dsl::sql_query};
 use diesel_async::RunQueryDsl;
 use kameo::actor::{ActorRef, Spawn as _};
--- a/server/crates/arbiter-server/tests/keyholder/lifecycle.rs
+++ b/server/crates/arbiter-server/tests/keyholder/lifecycle.rs
@@ -1,10 +1,9 @@
-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_server::{
    actors::keyholder::{Error, KeyHolder},
    crypto::encryption::v1::{Nonce, ROOT_KEY_TAG},
    db::{self, models, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
-
 use diesel::{QueryDsl, SelectableHelper};
 use diesel_async::RunQueryDsl;

--- a/server/crates/arbiter-server/tests/keyholder/storage.rs
+++ b/server/crates/arbiter-server/tests/keyholder/storage.rs
@@ -1,12 +1,11 @@
 use std::collections::HashSet;

-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_server::{
    actors::keyholder::Error,
    crypto::encryption::v1::Nonce,
    db::{self, models, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
-
 use diesel::{ExpressionMethods as _, QueryDsl, SelectableHelper, dsl::update};
 use diesel_async::RunQueryDsl;

--- a/server/crates/arbiter-server/tests/user_agent/auth.rs
+++ b/server/crates/arbiter-server/tests/user_agent/auth.rs
@@ -1,37 +1,21 @@
-use arbiter_crypto::{
-    authn::{self, USERAGENT_CONTEXT, format_challenge},
-    safecell::{SafeCell, SafeCellHandle as _},
-};
-
 use arbiter_proto::transport::{Receiver, Sender};
 use arbiter_server::{
    actors::{
        GlobalActors,
        bootstrap::GetToken,
        keyholder::Bootstrap,
-        user_agent::{UserAgentConnection, UserAgentCredentials, auth},
+        user_agent::{AuthPublicKey, UserAgentConnection, UserAgentCredentials, auth},
    },
    crypto::integrity,
    db::{self, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
 use diesel::{ExpressionMethods as _, QueryDsl, insert_into};
 use diesel_async::RunQueryDsl;
-use ml_dsa::{KeyGen, MlDsa87, SigningKey, signature::Keypair as _};
+use ed25519_dalek::Signer as _;

 use super::common::ChannelTransport;

-fn sign_useragent_challenge(
-    key: &SigningKey<MlDsa87>,
-    nonce: i32,
-    pubkey_bytes: &[u8],
-) -> authn::Signature {
-    let challenge = format_challenge(nonce, pubkey_bytes);
-    key.signing_key()
-        .sign_deterministic(&challenge, USERAGENT_CONTEXT)
-        .unwrap()
-        .into()
-}
-
 #[tokio::test]
 #[test_log::test]
 pub async fn test_bootstrap_token_auth() {
@@ -53,10 +37,10 @@ pub async fn test_bootstrap_token_auth() {
        auth::authenticate(&mut props, server_transport).await
    });

-    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
            bootstrap_token: Some(token),
        })
        .await
@@ -79,7 +63,7 @@ pub async fn test_bootstrap_token_auth() {
        .first::<Vec<u8>>(&mut conn)
        .await
        .unwrap();
-    assert_eq!(stored_pubkey, new_key.verifying_key().encode().to_vec());
+    assert_eq!(stored_pubkey, new_key.verifying_key().to_bytes().to_vec());
 }

 #[tokio::test]
@@ -95,10 +79,10 @@ pub async fn test_bootstrap_invalid_token_auth() {
        auth::authenticate(&mut props, server_transport).await
    });

-    let new_key = MlDsa87::key_gen(&mut rand::rng());
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
            bootstrap_token: Some("invalid_token".to_string()),
        })
        .await
@@ -131,8 +115,8 @@ pub async fn test_challenge_auth() {
        .await
        .unwrap();

-    let new_key = MlDsa87::key_gen(&mut rand::rng());
-    let pubkey_bytes = new_key.verifying_key().encode().to_vec();
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();

    {
        let mut conn = db.get().await.unwrap();
@@ -149,7 +133,7 @@ pub async fn test_challenge_auth() {
            &mut conn,
            &actors.key_holder,
            &UserAgentCredentials {
-                pubkey: new_key.verifying_key().into(),
+                pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
                nonce: 1,
            },
            id,
@@ -167,7 +151,7 @@ pub async fn test_challenge_auth() {

    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
            bootstrap_token: None,
        })
        .await
@@ -185,11 +169,12 @@ pub async fn test_challenge_auth() {
        Err(err) => panic!("Expected Ok response, got Err({err:?})"),
    };

-    let signature = sign_useragent_challenge(&new_key, challenge, &pubkey_bytes);
+    let formatted_challenge = arbiter_proto::format_challenge(challenge, &pubkey_bytes);
+    let signature = new_key.sign(&formatted_challenge);

    test_transport
        .send(auth::Inbound::AuthChallengeSolution {
-            signature: signature.to_bytes(),
+            signature: signature.to_bytes().to_vec(),
        })
        .await
        .unwrap();
@@ -220,8 +205,8 @@ pub async fn test_challenge_auth_rejects_integrity_tag_mismatch_when_unsealed()
        .await
        .unwrap();

-    let new_key = MlDsa87::key_gen(&mut rand::rng());
-    let pubkey_bytes = new_key.verifying_key().encode().to_vec();
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();

    {
        let mut conn = db.get().await.unwrap();
@@ -244,7 +229,7 @@ pub async fn test_challenge_auth_rejects_integrity_tag_mismatch_when_unsealed()

    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
            bootstrap_token: None,
        })
        .await
@@ -269,8 +254,8 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
        .await
        .unwrap();

-    let new_key = MlDsa87::key_gen(&mut rand::rng());
-    let pubkey_bytes = new_key.verifying_key().encode().to_vec();
+    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let pubkey_bytes = new_key.verifying_key().to_bytes().to_vec();

    {
        let mut conn = db.get().await.unwrap();
@@ -287,7 +272,7 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
            &mut conn,
            &actors.key_holder,
            &UserAgentCredentials {
-                pubkey: new_key.verifying_key().into(),
+                pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
                nonce: 1,
            },
            id,
@@ -305,7 +290,7 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {

    test_transport
        .send(auth::Inbound::AuthChallengeRequest {
-            pubkey: new_key.verifying_key().into(),
+            pubkey: AuthPublicKey::Ed25519(new_key.verifying_key()),
            bootstrap_token: None,
        })
        .await
@@ -323,11 +308,12 @@ pub async fn test_challenge_auth_rejects_invalid_signature() {
        Err(err) => panic!("Expected Ok response, got Err({err:?})"),
    };

-    let signature = sign_useragent_challenge(&new_key, challenge + 1, &pubkey_bytes);
+    let wrong_challenge = arbiter_proto::format_challenge(challenge + 1, &pubkey_bytes);
+    let signature = new_key.sign(&wrong_challenge);

    test_transport
        .send(auth::Inbound::AuthChallengeSolution {
-            signature: signature.to_bytes(),
+            signature: signature.to_bytes().to_vec(),
        })
        .await
        .unwrap();
--- a/server/crates/arbiter-server/tests/user_agent/unseal.rs
+++ b/server/crates/arbiter-server/tests/user_agent/unseal.rs
@@ -1,4 +1,3 @@
-use arbiter_crypto::safecell::{SafeCell, SafeCellHandle as _};
 use arbiter_server::{
    actors::{
        GlobalActors,
@@ -9,8 +8,8 @@ use arbiter_server::{
        },
    },
    db,
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
-
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
 use kameo::actor::Spawn as _;
 use x25519_dalek::{EphemeralSecret, PublicKey};