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

fix(server::bootsrapper): token compare is now constant-time
tests(server::client::auth): integrity envelope insertion for valid paths
2026-04-07 21:12:36 +02:00 · 2026-04-06 18:33:47 +02:00 · 2026-04-06 18:24:13 +02:00 · 2026-04-06 18:13:11 +02:00 · 2026-04-06 15:42:47 +00:00 · 2026-04-06 17:40:41 +02:00
36 changed files with 1550 additions and 475 deletions
--- a/mise.lock
+++ b/mise.lock
@@ -48,6 +48,10 @@ backend = "cargo:cargo-features-manager"
 version = "1.46.3"
 backend = "cargo:cargo-insta"

+[[tools."cargo:cargo-mutants"]]
+version = "27.0.0"
+backend = "cargo:cargo-mutants"
+
 [[tools."cargo:cargo-nextest"]]
 version = "0.9.126"
 backend = "cargo:cargo-nextest"
@@ -111,30 +115,37 @@ backend = "core:python"
 [tools.python."platforms.linux-arm64"]
 checksum = "sha256:53700338695e402a1a1fe22be4a41fbdacc70e22bb308a48eca8ed67cb7992be"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"

 [tools.python."platforms.linux-arm64-musl"]
 checksum = "sha256:53700338695e402a1a1fe22be4a41fbdacc70e22bb308a48eca8ed67cb7992be"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"

 [tools.python."platforms.linux-x64"]
 checksum = "sha256:d7a9f970914bb4c88756fe3bdcc186d4feb90e9500e54f1db47dae4dc9687e39"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"

 [tools.python."platforms.linux-x64-musl"]
 checksum = "sha256:d7a9f970914bb4c88756fe3bdcc186d4feb90e9500e54f1db47dae4dc9687e39"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz"
+provenance = "github-attestations"

 [tools.python."platforms.macos-arm64"]
 checksum = "sha256:c43aecde4a663aebff99b9b83da0efec506479f1c3f98331442f33d2c43501f9"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-aarch64-apple-darwin-install_only_stripped.tar.gz"
+provenance = "github-attestations"

 [tools.python."platforms.macos-x64"]
 checksum = "sha256:9ab41dbc2f100a2a45d1833b9c11165f51051c558b5213eda9a9731d5948a0c0"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-apple-darwin-install_only_stripped.tar.gz"
+provenance = "github-attestations"

 [tools.python."platforms.windows-x64"]
 checksum = "sha256:bbe19034b35b0267176a7442575ae7dc6343480fd4d35598cb7700173d431e09"
 url = "https://github.com/astral-sh/python-build-standalone/releases/download/20260324/cpython-3.14.3+20260324-x86_64-pc-windows-msvc-install_only_stripped.tar.gz"
+provenance = "github-attestations"

 [[tools.rust]]
 version = "1.93.0"
--- a/mise.toml
+++ b/mise.toml
@@ -12,6 +12,7 @@ protoc = "29.6"
 python = "3.14.3"
 ast-grep = "0.42.0"
 "cargo:cargo-edit" = "0.13.9"
+"cargo:cargo-mutants" = "27.0.0"

 [tasks.codegen]
 sources = ['protobufs/*.proto', 'protobufs/**/*.proto']
--- a/protobufs/shared/evm.proto
+++ b/protobufs/shared/evm.proto
@@ -36,6 +36,10 @@ message GasLimitExceededViolation {
 }

 message EvalViolation {
+  message ChainIdMismatch {
+    uint64 expected = 1;
+    uint64 actual = 2;
+  }
  oneof kind {
    bytes invalid_target = 1; // 20-byte Ethereum address
    GasLimitExceededViolation gas_limit_exceeded = 2;
@@ -43,6 +47,8 @@ message EvalViolation {
    google.protobuf.Empty volumetric_limit_exceeded = 4;
    google.protobuf.Empty invalid_time = 5;
    google.protobuf.Empty invalid_transaction_type = 6;
+
+    ChainIdMismatch chain_id_mismatch = 7;
  }
 }

--- a/server/.cargo/mutants.toml
+++ b/server/.cargo/mutants.toml
@@ -0,0 +1 @@
+test_tool = "nextest"
--- a/server/.gitignore
+++ b/server/.gitignore
@@ -0,0 +1,2 @@
+mutants.out/
+mutants.out.old/
--- a/server/Cargo.lock
+++ b/server/Cargo.lock
@@ -743,22 +743,24 @@ dependencies = [
 "k256",
 "kameo",
 "memsafe",
+ "mutants",
 "pem",
- "postcard",
+ "proptest",
 "prost",
 "prost-types",
 "rand 0.10.0",
 "rcgen",
 "restructed",
 "rsa",
+ "rstest",
 "rustls",
 "secrecy",
- "serde",
 "serde_with",
 "sha2 0.10.9",
 "smlang",
 "spki",
 "strum 0.28.0",
+ "subtle",
 "test-log",
 "thiserror 2.0.18",
 "tokio",
@@ -1057,15 +1059,6 @@ dependencies = [
 "syn 2.0.117",
 ]

-[[package]]
-name = "atomic-polyfill"
-version = "1.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8cf2bce30dfe09ef0bfaef228b9d414faaf7e563035494d7fe092dba54b300f4"
-dependencies = [
- "critical-section",
-]
-
 [[package]]
 name = "atomic-waker"
 version = "1.1.2"
@@ -1456,15 +1449,6 @@ dependencies = [
 "cc",
 ]

-[[package]]
-name = "cobs"
-version = "0.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0fa961b519f0b462e3a3b4a34b64d119eeaca1d59af726fe450bbba07a9fc0a1"
-dependencies = [
- "thiserror 2.0.18",
-]
-
 [[package]]
 name = "console"
 version = "0.15.11"
@@ -1572,12 +1556,6 @@ dependencies = [
 "cfg-if",
 ]

-[[package]]
-name = "critical-section"
-version = "1.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "790eea4361631c5e7d22598ecd5723ff611904e3344ce8720784c93e3d83d40b"
-
 [[package]]
 name = "crossbeam-utils"
 version = "0.8.21"
@@ -2043,18 +2021,6 @@ dependencies = [
 "zeroize",
 ]

-[[package]]
-name = "embedded-io"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef1a6892d9eef45c8fa6b9e0086428a2cca8491aca8f787c534a3d6d0bcb3ced"
-
-[[package]]
-name = "embedded-io"
-version = "0.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "edd0f118536f44f5ccd48bcb8b111bdc3de888b58c74639dfb034a357d0f206d"
-
 [[package]]
 name = "encode_unicode"
 version = "1.0.0"
@@ -2472,15 +2438,6 @@ dependencies = [
 "tracing",
 ]

-[[package]]
-name = "hash32"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0c35f58762feb77d74ebe43bdbc3210f09be9fe6742234d573bacc26ed92b67"
-dependencies = [
- "byteorder",
-]
-
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -2515,20 +2472,6 @@ dependencies = [
 "serde_core",
 ]

-[[package]]
-name = "heapless"
-version = "0.7.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cdc6457c0eb62c71aac4bc17216026d8410337c4126773b9c5daba343f17964f"
-dependencies = [
- "atomic-polyfill",
- "hash32",
- "rustc_version 0.4.1",
- "serde",
- "spin",
- "stable_deref_trait",
-]
-
 [[package]]
 name = "heck"
 version = "0.5.0"
@@ -3236,6 +3179,12 @@ version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1d87ecb2933e8aeadb3e3a02b828fed80a7528047e68b4f424523a0981a3a084"

+[[package]]
+name = "mutants"
+version = "0.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "add0ac067452ff1aca8c5002111bd6b1c895baee6e45fcbc44e0193aea17be56"
+
 [[package]]
 name = "nom"
 version = "7.1.3"
@@ -3589,19 +3538,6 @@ version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"

-[[package]]
-name = "postcard"
-version = "1.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6764c3b5dd454e283a30e6dfe78e9b31096d9e32036b5d1eaac7a6119ccb9a24"
-dependencies = [
- "cobs",
- "embedded-io 0.4.0",
- "embedded-io 0.6.1",
- "heapless",
- "serde",
-]
-
 [[package]]
 name = "potential_utf"
 version = "0.1.4"
@@ -3713,9 +3649,9 @@ dependencies = [

 [[package]]
 name = "proptest"
-version = "1.10.0"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "37566cb3fdacef14c0737f9546df7cfeadbfbc9fef10991038bf5015d0c80532"
+checksum = "4b45fcc2344c680f5025fe57779faef368840d0bd1f42f216291f0dc4ace4744"
 dependencies = [
 "bit-set",
 "bit-vec",
@@ -4790,9 +4726,6 @@ name = "spin"
 version = "0.9.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
-dependencies = [
- "lock_api",
-]

 [[package]]
 name = "spki"
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -44,3 +44,4 @@ sha2 = "0.10"
 spki = "0.7"
 prost = "0.14.3"
 miette = { version = "7.6.0", features = ["fancy", "serde"] }
+mutants = "0.0.4"
--- 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/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-server/Cargo.toml
+++ b/server/crates/arbiter-server/Cargo.toml
@@ -58,10 +58,12 @@ prost-types.workspace = true
 prost.workspace = true
 arbiter-tokens-registry.path = "../arbiter-tokens-registry"
 anyhow = "1.0.102"
-postcard = { version = "1.1.3", features = ["use-std"] }
-serde = { version = "1.0.228", features = ["derive"] }
 serde_with = "3.18.0"
+mutants.workspace = true
+subtle = "2.6.1"

 [dev-dependencies]
 insta = "1.46.3"
+proptest = "1.11.0"
+rstest.workspace = true
 test-log = { version = "0.2", default-features = false, features = ["trace"] }
--- a/server/crates/arbiter-server/src/actors/bootstrap.rs
+++ b/server/crates/arbiter-server/src/actors/bootstrap.rs
@@ -4,6 +4,7 @@ use diesel_async::RunQueryDsl;
 use kameo::{Actor, messages};

 use rand::{RngExt, distr::Alphanumeric, make_rng, rngs::StdRng};
+use subtle::ConstantTimeEq as _;
 use thiserror::Error;

 use crate::db::{self, DatabasePool, schema};
@@ -44,14 +45,14 @@ pub struct Bootstrapper {

 impl Bootstrapper {
    pub async fn new(db: &DatabasePool) -> Result<Self, Error> {
-        let mut conn = db.get().await?;
+        let row_count: i64 = {
+            let mut conn = db.get().await?;

-        let row_count: i64 = schema::useragent_client::table
-            .count()
-            .get_result(&mut conn)
-            .await?;
-
-        drop(conn);
+            schema::useragent_client::table
+                .count()
+                .get_result(&mut conn)
+                .await?
+        };

        let token = if row_count == 0 {
            let token = generate_token().await?;
@@ -69,7 +70,13 @@ impl Bootstrapper {
    #[message]
    pub fn is_correct_token(&self, token: String) -> bool {
        match &self.token {
-            Some(expected) => *expected == token,
+            Some(expected) => {
+                let expected_bytes = expected.as_bytes();
+                let token_bytes = token.as_bytes();
+
+                let choice = expected_bytes.ct_eq(token_bytes);
+                bool::from(choice)
+            }
            None => false,
        }
    }
--- a/server/crates/arbiter-server/src/actors/client/auth.rs
+++ b/server/crates/arbiter-server/src/actors/client/auth.rs
@@ -9,14 +9,16 @@ use diesel::{
 };
 use diesel_async::RunQueryDsl as _;
 use ed25519_dalek::{Signature, VerifyingKey};
-use kameo::error::SendError;
+use kameo::{actor::ActorRef, error::SendError};
 use tracing::error;

 use crate::{
    actors::{
-        client::{ClientConnection, ClientProfile},
+        client::{ClientConnection, ClientCredentials, ClientProfile},
        flow_coordinator::{self, RequestClientApproval},
+        keyholder::KeyHolder,
    },
+    crypto::integrity::{self},
    db::{
        self,
        models::{ProgramClientMetadata, SqliteTimestamp},
@@ -30,6 +32,8 @@ pub enum Error {
    DatabasePoolUnavailable,
    #[error("Database operation failed")]
    DatabaseOperationFailed,
+    #[error("Integrity check failed")]
+    IntegrityCheckFailed,
    #[error("Invalid challenge solution")]
    InvalidChallengeSolution,
    #[error("Client approval request failed")]
@@ -38,6 +42,13 @@ pub enum Error {
    Transport,
 }

+impl From<diesel::result::Error> for Error {
+    fn from(e: diesel::result::Error) -> Self {
+        error!(?e, "Database error");
+        Self::DatabaseOperationFailed
+    }
+}
+
 #[derive(thiserror::Error, Debug, Clone, PartialEq, Eq)]
 pub enum ApproveError {
    #[error("Internal error")]
@@ -65,17 +76,69 @@ pub enum Outbound {
    AuthSuccess,
 }

-pub struct ClientInfo {
-    pub id: i32,
-    pub current_nonce: i32,
-}
-
-/// Atomically reads and increments the nonce for a known client.
+/// Returns the current nonce and client ID for a registered client.
 /// Returns `None` if the pubkey is not registered.
-async fn get_client_and_nonce(
+async fn get_current_nonce_and_id(
    db: &db::DatabasePool,
    pubkey: &VerifyingKey,
-) -> Result<Option<ClientInfo>, Error> {
+) -> Result<Option<(i32, i32)>, Error> {
+    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
+    })?;
+    program_client::table
+        .filter(program_client::public_key.eq(&pubkey_bytes))
+        .select((program_client::id, program_client::nonce))
+        .first::<(i32, i32)>(&mut conn)
+        .await
+        .optional()
+        .map_err(|e| {
+            error!(error = ?e, "Database error");
+            Error::DatabaseOperationFailed
+        })
+}
+
+async fn verify_integrity(
+    db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &VerifyingKey,
+) -> Result<(), Error> {
+    let mut db_conn = db.get().await.map_err(|e| {
+        error!(error = ?e, "Database pool error");
+        Error::DatabasePoolUnavailable
+    })?;
+
+    let (id, nonce) = get_current_nonce_and_id(db, pubkey).await?.ok_or_else(|| {
+        error!("Client not found during integrity verification");
+        Error::DatabaseOperationFailed
+    })?;
+
+    integrity::verify_entity(
+        &mut db_conn,
+        keyholder,
+        &ClientCredentials {
+            pubkey: *pubkey,
+            nonce,
+        },
+        id,
+    )
+    .await
+    .map_err(|e| {
+        error!(?e, "Integrity verification failed");
+        Error::IntegrityCheckFailed
+    })?;
+
+    Ok(())
+}
+
+/// Atomically increments the nonce and re-signs the integrity envelope.
+/// Returns the new nonce, which is used as the challenge nonce.
+async fn create_nonce(
+    db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
+    pubkey: &VerifyingKey,
+) -> Result<i32, Error> {
    let pubkey_bytes = pubkey.as_bytes().to_vec();

    let mut conn = db.get().await.map_err(|e| {
@@ -84,34 +147,34 @@ async fn get_client_and_nonce(
    })?;

    conn.exclusive_transaction(|conn| {
+        let keyholder = keyholder.clone();
        Box::pin(async move {
-            let Some((client_id, current_nonce)) = program_client::table
+            let (id, new_nonce): (i32, i32) = update(program_client::table)
                .filter(program_client::public_key.eq(&pubkey_bytes))
-                .select((program_client::id, program_client::nonce))
-                .first::<(i32, i32)>(conn)
-                .await
-                .optional()?
-            else {
-                return Result::<_, diesel::result::Error>::Ok(None);
-            };
-
-            update(program_client::table)
-                .filter(program_client::public_key.eq(&pubkey_bytes))
-                .set(program_client::nonce.eq(current_nonce + 1))
-                .execute(conn)
+                .set(program_client::nonce.eq(program_client::nonce + 1))
+                .returning((program_client::id, program_client::nonce))
+                .get_result(conn)
                .await?;

-            Ok(Some(ClientInfo {
-                id: client_id,
-                current_nonce,
-            }))
+            integrity::sign_entity(
+                conn,
+                &keyholder,
+                &ClientCredentials {
+                    pubkey: *pubkey,
+                    nonce: new_nonce,
+                },
+                id,
+            )
+            .await
+            .map_err(|e| {
+                error!(?e, "Integrity sign failed after nonce update");
+                Error::DatabaseOperationFailed
+            })?;
+
+            Ok(new_nonce)
        })
    })
    .await
-    .map_err(|e| {
-        error!(error = ?e, "Database error");
-        Error::DatabaseOperationFailed
-    })
 }

 async fn approve_new_client(
@@ -139,45 +202,63 @@ async fn approve_new_client(

 async fn insert_client(
    db: &db::DatabasePool,
+    keyholder: &ActorRef<KeyHolder>,
    pubkey: &VerifyingKey,
    metadata: &ClientMetadata,
 ) -> Result<i32, Error> {
    use crate::db::schema::{client_metadata, program_client};
+    let metadata = metadata.clone();
+
    let mut conn = db.get().await.map_err(|e| {
        error!(error = ?e, "Database pool error");
        Error::DatabasePoolUnavailable
    })?;

-    let metadata_id = insert_into(client_metadata::table)
-        .values((
-            client_metadata::name.eq(&metadata.name),
-            client_metadata::description.eq(&metadata.description),
-            client_metadata::version.eq(&metadata.version),
-        ))
-        .returning(client_metadata::id)
-        .get_result::<i32>(&mut conn)
-        .await
-        .map_err(|e| {
-            error!(error = ?e, "Failed to insert client metadata");
-            Error::DatabaseOperationFailed
-        })?;
+    conn.exclusive_transaction(|conn| {
+        let keyholder = keyholder.clone();
+        Box::pin(async move {
+            const NONCE_START: i32 = 1;

-    let client_id = insert_into(program_client::table)
-        .values((
-            program_client::public_key.eq(pubkey.as_bytes().to_vec()),
-            program_client::metadata_id.eq(metadata_id),
-            program_client::nonce.eq(1), // pre-incremented; challenge uses 0
-        ))
-        .on_conflict_do_nothing()
-        .returning(program_client::id)
-        .get_result::<i32>(&mut conn)
-        .await
-        .map_err(|e| {
-            error!(error = ?e, "Failed to insert client metadata");
-            Error::DatabaseOperationFailed
-        })?;
+            let metadata_id = insert_into(client_metadata::table)
+                .values((
+                    client_metadata::name.eq(&metadata.name),
+                    client_metadata::description.eq(&metadata.description),
+                    client_metadata::version.eq(&metadata.version),
+                ))
+                .returning(client_metadata::id)
+                .get_result::<i32>(conn)
+                .await?;

-    Ok(client_id)
+            let client_id = insert_into(program_client::table)
+                .values((
+                    program_client::public_key.eq(pubkey.as_bytes().to_vec()),
+                    program_client::metadata_id.eq(metadata_id),
+                    program_client::nonce.eq(NONCE_START),
+                ))
+                .on_conflict_do_nothing()
+                .returning(program_client::id)
+                .get_result::<i32>(conn)
+                .await?;
+
+            integrity::sign_entity(
+                conn,
+                &keyholder,
+                &ClientCredentials {
+                    pubkey: *pubkey,
+                    nonce: NONCE_START,
+                },
+                client_id,
+            )
+            .await
+            .map_err(|e| {
+                error!(error = ?e, "Failed to sign integrity tag for new client key");
+                Error::DatabaseOperationFailed
+            })?;
+
+            Ok(client_id)
+        })
+    })
+    .await
 }

 async fn sync_client_metadata(
@@ -295,8 +376,11 @@ where
        return Err(Error::Transport);
    };

-    let info = match get_client_and_nonce(&props.db, &pubkey).await? {
-        Some(nonce) => nonce,
+    let client_id = match get_current_nonce_and_id(&props.db, &pubkey).await? {
+        Some((id, _)) => {
+            verify_integrity(&props.db, &props.actors.key_holder, &pubkey).await?;
+            id
+        }
        None => {
            approve_new_client(
                &props.actors,
@@ -306,16 +390,13 @@ where
                },
            )
            .await?;
-            let client_id = insert_client(&props.db, &pubkey, &metadata).await?;
-            ClientInfo {
-                id: client_id,
-                current_nonce: 0,
-            }
+            insert_client(&props.db, &props.actors.key_holder, &pubkey, &metadata).await?
        }
    };

-    sync_client_metadata(&props.db, info.id, &metadata).await?;
-    challenge_client(transport, pubkey, info.current_nonce).await?;
+    sync_client_metadata(&props.db, client_id, &metadata).await?;
+    let challenge_nonce = create_nonce(&props.db, &props.actors.key_holder, &pubkey).await?;
+    challenge_client(transport, pubkey, challenge_nonce).await?;

    transport
        .send(Ok(Outbound::AuthSuccess))
@@ -325,5 +406,5 @@ where
            Error::Transport
        })?;

-    Ok(info.id)
+    Ok(client_id)
 }
--- a/server/crates/arbiter-server/src/actors/client/mod.rs
+++ b/server/crates/arbiter-server/src/actors/client/mod.rs
@@ -4,6 +4,7 @@ use tracing::{error, info};

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

@@ -13,6 +14,22 @@ pub struct ClientProfile {
    pub metadata: ClientMetadata,
 }

+pub struct ClientCredentials {
+    pub pubkey: ed25519_dalek::VerifyingKey,
+    pub nonce: i32,
+}
+
+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,
--- a/server/crates/arbiter-server/src/actors/evm/mod.rs
+++ b/server/crates/arbiter-server/src/actors/evm/mod.rs
@@ -7,18 +7,19 @@ use kameo::{Actor, actor::ActorRef, messages};
 use rand::{SeedableRng, rng, rngs::StdRng};

 use crate::{
-    actors::keyholder::{CreateNew, Decrypt, GetState, KeyHolder, KeyHolderState},
+    actors::keyholder::{CreateNew, Decrypt, KeyHolder},
    crypto::integrity,
    db::{
        DatabaseError, DatabasePool,
-        models::{self, SqliteTimestamp},
+        models::{self},
        schema,
    },
    evm::{
-        self, ListError, RunKind, policies::{
+        self, ListError, RunKind,
+        policies::{
            CombinedSettings, Grant, SharedGrantSettings, SpecificGrant, SpecificMeaning,
            ether_transfer::EtherTransfer, token_transfers::TokenTransfer,
-        }
+        },
    },
    safe_cell::{SafeCell, SafeCellHandle as _},
 };
@@ -135,7 +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
@@ -157,7 +158,7 @@ impl EvmActor {
    }

    #[message]
-    pub async fn useragent_delete_grant(&mut self, grant_id: i32) -> Result<(), Error> {
+    pub async fn useragent_delete_grant(&mut self, _grant_id: i32) -> Result<(), Error> {
        // let mut conn = self.db.get().await.map_err(DatabaseError::from)?;
        // let keyholder = self.keyholder.clone();

--- a/server/crates/arbiter-server/src/actors/user_agent/auth.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/auth.rs
@@ -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)
    }
 }

--- a/server/crates/arbiter-server/src/actors/user_agent/auth/state.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/auth/state.rs
@@ -1,7 +1,7 @@
 use arbiter_proto::transport::Bi;
 use diesel::{ExpressionMethods as _, OptionalExtension as _, QueryDsl, update};
 use diesel_async::{AsyncConnection, RunQueryDsl};
-use kameo::{actor::ActorRef, error::SendError};
+use kameo::actor::ActorRef;
 use tracing::error;

 use super::Error;
@@ -11,7 +11,7 @@ use crate::{
        keyholder::KeyHolder,
        user_agent::{AuthPublicKey, UserAgentConnection, UserAgentCredentials, auth::Outbound},
    },
-    crypto::integrity::{self, AttestationStatus},
+    crypto::integrity,
    db::{DatabasePool, schema::useragent_client},
 };

@@ -48,10 +48,10 @@ async fn get_current_nonce_and_id(
    db: &DatabasePool,
    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 {
@@ -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
@@ -80,14 +77,14 @@ async fn verify_integrity(
    keyholder: &ActorRef<KeyHolder>,
    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 {
@@ -97,13 +94,17 @@ async fn verify_integrity(
        id,
    )
    .await
-    .map_err(|e| {
-        error!(?e, "Integrity verification failed");
-        Error::internal("Integrity verification failed")
-    })?;
-
-    Ok(())
+    .map_err(|e| Error::internal("Integrity verification failed", &e))?;

+    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(
@@ -111,10 +112,10 @@ async fn create_nonce(
    keyholder: &ActorRef<KeyHolder>,
    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 {
@@ -125,10 +126,7 @@ async fn create_nonce(
                    .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,
@@ -140,10 +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)
            })
@@ -159,10 +154,10 @@ async fn register_key(
 ) -> Result<(), Error> {
    let pubkey_bytes = pubkey.to_stored_bytes();
    let key_type = pubkey.key_type();
-    let mut conn = db.get().await.map_err(|e| {
-        error!(error = ?e, "Database pool error");
-        Error::internal("Database unavailable")
-    })?;
+    let mut conn = db
+        .get()
+        .await
+        .map_err(|e| Error::internal("Database unavailable", &e))?;

    conn.transaction(|conn| {
        Box::pin(async move {
@@ -177,22 +172,32 @@ async fn register_key(
                .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(())
        })
@@ -255,10 +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");
--- a/server/crates/arbiter-server/src/actors/user_agent/mod.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/mod.rs
@@ -1,59 +1,23 @@
 use crate::{
-    actors::{GlobalActors, client::ClientProfile}, crypto::integrity::Integrable, db::{self, models::KeyType}
+    actors::{GlobalActors, client::ClientProfile},
+    crypto::integrity::Integrable,
+    db::{self, models::KeyType},
 };

-fn serialize_ecdsa<S>(key: &k256::ecdsa::VerifyingKey, serializer: S) -> Result<S::Ok, S::Error>
-where
-    S: serde::Serializer,
-{
-    // Serialize as hex string for easier debugging (33 bytes compressed SEC1 format)
-    let key = key.to_encoded_point(true);
-    let bytes = key.as_bytes();
-    serializer.serialize_bytes(bytes)
-}
-
-fn deserialize_ecdsa<'de, D>(deserializer: D) -> Result<k256::ecdsa::VerifyingKey, D::Error>
-where
-    D: serde::Deserializer<'de>,
-{
-    struct EcdsaVisitor;
-
-    impl<'de> serde::de::Visitor<'de> for EcdsaVisitor {
-        type Value = k256::ecdsa::VerifyingKey;
-
-        fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-            formatter.write_str("a compressed SEC1-encoded ECDSA public key")
-        }
-
-        fn visit_bytes<E>(self, v: &[u8]) -> Result<Self::Value, E>
-        where
-            E: serde::de::Error,
-        {
-            let point = k256::EncodedPoint::from_bytes(v)
-                .map_err(|_| E::custom("invalid compressed SEC1 format"))?;
-            k256::ecdsa::VerifyingKey::from_encoded_point(&point)
-                .map_err(|_| E::custom("invalid ECDSA public key"))
-        }
-    }
-
-    deserializer.deserialize_bytes(EcdsaVisitor)
-}
-
 /// Abstraction over Ed25519 / ECDSA-secp256k1 / RSA public keys used during the auth handshake.
-#[derive(Clone, Debug, Serialize)]
+#[derive(Clone, Debug)]
 pub enum AuthPublicKey {
    Ed25519(ed25519_dalek::VerifyingKey),
    /// Compressed SEC1 public key; signature bytes are raw 64-byte (r||s).
-    #[serde(serialize_with = "serialize_ecdsa", deserialize_with = "deserialize_ecdsa")]
    EcdsaSecp256k1(k256::ecdsa::VerifyingKey),
    /// RSA-2048+ public key (Windows Hello / KeyCredentialManager); signature bytes are PSS+SHA-256.
    Rsa(rsa::RsaPublicKey),
 }

-#[derive(Debug, Serialize)]
+#[derive(Debug)]
 pub struct UserAgentCredentials {
    pub pubkey: AuthPublicKey,
-    pub nonce: i32
+    pub nonce: i32,
 }

 impl Integrable for UserAgentCredentials {
@@ -138,5 +102,19 @@ pub mod auth;
 pub mod session;

 pub use auth::authenticate;
-use serde::Serialize;
 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/connection.rs
+++ b/server/crates/arbiter-server/src/actors/user_agent/session/connection.rs
@@ -10,7 +10,6 @@ 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::db::models::{
@@ -18,6 +17,10 @@ use crate::db::models::{
 };
 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::{
@@ -29,11 +32,66 @@ use crate::{
            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)
@@ -365,10 +429,13 @@ impl UserAgentSession {
            .props
            .actors
            .evm
-            .ask(UseragentDeleteGrant { grant_id })
+            .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)
--- a/server/crates/arbiter-server/src/crypto/integrity/v1.rs
+++ b/server/crates/arbiter-server/src/crypto/integrity/v1.rs
@@ -1,19 +1,23 @@
-use crate::{actors::keyholder, crypto::KeyCell,safe_cell::SafeCellHandle as _};
-use chacha20poly1305::Key;
-use hmac::{Hmac, Mac as _};
-use serde::Serialize;
+use crate::actors::keyholder;
+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,
    },
 };
@@ -43,29 +47,52 @@ pub enum Error {

    #[error("Integrity MAC mismatch for entity {entity_kind}")]
    MacMismatch { entity_kind: &'static str },
-
-    #[error("Payload serialization error: {0}")]
-    PayloadSerialization(#[from] postcard::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";

 pub type HmacSha256 = Hmac<Sha256>;

-pub trait Integrable: Serialize {
+pub trait Integrable: Hashable {
    const KIND: &'static str;
    const VERSION: i32 = 1;
 }

-fn payload_hash(payload: &[u8]) -> [u8; 32] {
-    Sha256::digest(payload).into()
+fn payload_hash(payload: &impl Hashable) -> [u8; 32] {
+    let mut hasher = Sha256::new();
+    payload.hash(&mut hasher);
+    hasher.finalize().into()
 }

 fn push_len_prefixed(out: &mut Vec<u8>, bytes: &[u8]) {
@@ -87,32 +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 = postcard::to_stdvec(entity)?;
-    let payload_hash = payload_hash(&payload);
+    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);

@@ -127,8 +217,8 @@ pub async fn sign_entity<E: Integrable>(
    insert_into(integrity_envelope::table)
        .values(NewIntegrityEnvelope {
            entity_kind: E::KIND.to_owned(),
-            entity_id: entity_id,
-            payload_version: E::VERSION ,
+            entity_id: entity_id.to_vec(),
+            payload_version: E::VERSION,
            key_version,
            mac: mac.to_vec(),
        })
@@ -146,23 +236,25 @@ 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 {
-            diesel::result::Error::NotFound => Error::MissingEnvelope { entity_kind: E::KIND },
+            diesel::result::Error::NotFound => Error::MissingEnvelope {
+                entity_kind: E::KIND,
+            },
            other => Error::Database(db::DatabaseError::from(other)),
        })?;

@@ -174,14 +266,8 @@ pub async fn verify_entity<E: Integrable>(
        });
    }

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

    let result = keyholder
        .ask(VerifyIntegrity {
@@ -189,22 +275,56 @@ pub async fn verify_entity<E: Integrable>(
            expected_mac: envelope.mac,
            key_version: envelope.key_version,
        })
-        .await
-        ;
+        .await;

    match result {
        Ok(true) => Ok(AttestationStatus::Attested),
-        Ok(false) => Err(Error::MacMismatch { entity_kind: E::KIND }),
-        Err(SendError::HandlerError(keyholder::Error::NotBootstrapped)) => Ok(AttestationStatus::Unavailable),
+        Ok(false) => Err(Error::MacMismatch {
+            entity_kind: E::KIND,
+        }),
+        Err(SendError::HandlerError(keyholder::Error::NotBootstrapped)) => {
+            Ok(AttestationStatus::Unavailable)
+        }
        Err(_) => Err(Error::KeyholderSend),
    }
 }

+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},
@@ -212,14 +332,24 @@ mod tests {
        safe_cell::{SafeCell, SafeCellHandle as _},
    };

-    use super::{Error, Integrable, sign_entity, verify_entity};
+    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, serde::Serialize)]
+    #[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";
    }
@@ -248,7 +378,9 @@ mod tests {
            payload: b"payload-v1".to_vec(),
        };

-        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID).await.unwrap();
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();

        let count: i64 = schema::integrity_envelope::table
            .filter(schema::integrity_envelope::entity_kind.eq("dummy_entity"))
@@ -259,7 +391,9 @@ mod tests {
            .unwrap();

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

    #[tokio::test]
@@ -275,7 +409,9 @@ mod tests {
            payload: b"payload-v1".to_vec(),
        };

-        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID).await.unwrap();
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();

        diesel::update(schema::integrity_envelope::table)
            .filter(schema::integrity_envelope::entity_kind.eq("dummy_entity"))
@@ -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 { .. }));
@@ -304,16 +440,242 @@ mod tests {
            payload: b"payload-v1".to_vec(),
        };

-        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID).await.unwrap();
+        sign_entity(&mut conn, &keyholder, &entity, ENTITY_ID)
+            .await
+            .unwrap();

        let tampered = DummyEntity {
            payload: b"payload-v1-but-tampered".to_vec(),
            ..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
@@ -0,0 +1,107 @@
+use hmac::digest::Digest;
+use std::collections::HashSet;
+
+/// Deterministically hash a value by feeding its fields into the hasher in a consistent order.
+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());
+            }
+        }
+    )*
+};
+}
+
+impl_numeric!(u8, u16, u32, u64, i8, i16, i32, i64);
+
+impl Hashable for &[u8] {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self);
+    }
+}
+
+impl Hashable for String {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.as_bytes());
+    }
+}
+
+impl<T: Hashable + PartialOrd> Hashable for Vec<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        let ref_sorted = {
+            let mut sorted = self.iter().collect::<Vec<_>>();
+            sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
+            sorted
+        };
+        for item in ref_sorted {
+            item.hash(hasher);
+        }
+    }
+}
+
+impl<T: Hashable + PartialOrd> Hashable for HashSet<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        let ref_sorted = {
+            let mut sorted = self.iter().collect::<Vec<_>>();
+            sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
+            sorted
+        };
+        for item in ref_sorted {
+            item.hash(hasher);
+        }
+    }
+}
+
+impl<T: Hashable> Hashable for Option<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        match self {
+            Some(value) => {
+                hasher.update([1]);
+                value.hash(hasher);
+            }
+            None => hasher.update([0]),
+        }
+    }
+}
+
+impl<T: Hashable> Hashable for Box<T> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        self.as_ref().hash(hasher);
+    }
+}
+
+impl<T: Hashable> Hashable for &T {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        (*self).hash(hasher);
+    }
+}
+
+impl Hashable for alloy::primitives::Address {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.as_slice());
+    }
+}
+
+impl Hashable for alloy::primitives::U256 {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.to_be_bytes::<32>());
+    }
+}
+
+impl Hashable for chrono::Duration {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.num_seconds().to_be_bytes());
+    }
+}
+
+impl Hashable for chrono::DateTime<chrono::Utc> {
+    fn hash<H: Digest>(&self, hasher: &mut H) {
+        hasher.update(self.timestamp_millis().to_be_bytes());
+    }
+}
--- a/server/crates/arbiter-server/src/crypto/mod.rs
+++ b/server/crates/arbiter-server/src/crypto/mod.rs
@@ -102,11 +102,21 @@ impl KeyCell {
    }
 }

-/// User password might be of different length, have not enough entropy, etc...
 /// Derive a fixed-length key from the password using Argon2id, which is designed for password hashing and key derivation.
 pub fn derive_key(mut password: SafeCell<Vec<u8>>, salt: &Salt) -> KeyCell {
+    let params = {
+        #[cfg(debug_assertions)]
+        {
+            argon2::Params::new(8, 1, 1, None).unwrap()
+        }
+
+        #[cfg(not(debug_assertions))]
+        {
+            argon2::Params::new(262_144, 3, 4, None).unwrap()
+        }
+    };
+
    #[allow(clippy::unwrap_used)]
-    let params = argon2::Params::new(262_144, 3, 4, None).unwrap();
    let hasher = Argon2::new(Algorithm::Argon2id, argon2::Version::V0x13, params);
    let mut key = SafeCell::new(Key::default());
    password.read_inline(|password_source| {
--- a/server/crates/arbiter-server/src/db/mod.rs
+++ b/server/crates/arbiter-server/src/db/mod.rs
@@ -133,6 +133,7 @@ pub async fn create_pool(url: Option<&str>) -> Result<DatabasePool, DatabaseSetu
    Ok(pool)
 }

+#[mutants::skip]
 pub async fn create_test_pool() -> DatabasePool {
    use rand::distr::{Alphanumeric, SampleString as _};

--- 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::{
@@ -21,8 +21,8 @@ use crate::{
        schema::{self, evm_transaction_log},
    },
    evm::policies::{
-        DatabaseID, EvalContext, EvalViolation, Grant, Policy, CombinedSettings, SharedGrantSettings,
-        SpecificGrant, SpecificMeaning, ether_transfer::EtherTransfer,
+        CombinedSettings, DatabaseID, EvalContext, EvalViolation, Grant, Policy,
+        SharedGrantSettings, SpecificGrant, SpecificMeaning, ether_transfer::EtherTransfer,
        token_transfers::TokenTransfer,
    },
 };
@@ -90,6 +90,14 @@ async fn check_shared_constraints(
    let mut violations = Vec::new();
    let now = Utc::now();

+    if shared.chain != context.chain {
+        violations.push(EvalViolation::MismatchingChainId {
+            expected: shared.chain,
+            actual: context.chain,
+        });
+        return Ok(violations);
+    }
+
    // Validity window
    if shared.valid_from.is_some_and(|t| now < t) || shared.valid_until.is_some_and(|t| now > t) {
        violations.push(EvalViolation::InvalidTime);
@@ -145,12 +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,
@@ -206,7 +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,
    {
@@ -250,16 +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?;
@@ -270,7 +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>,
    {
@@ -278,16 +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> {
@@ -342,3 +380,255 @@ impl Engine {
        Err(VetError::UnsupportedTransactionType)
    }
 }
+
+#[cfg(test)]
+mod tests {
+    use alloy::primitives::{Address, Bytes, U256, address};
+    use chrono::{Duration, Utc};
+    use diesel::{SelectableHelper, insert_into};
+    use diesel_async::RunQueryDsl;
+    use rstest::rstest;
+
+    use crate::db::{
+        self, DatabaseConnection,
+        models::{
+            EvmBasicGrant, EvmWalletAccess, NewEvmBasicGrant, NewEvmTransactionLog, SqliteTimestamp,
+        },
+        schema::{evm_basic_grant, evm_transaction_log},
+    };
+    use crate::evm::policies::{
+        EvalContext, EvalViolation, SharedGrantSettings, TransactionRateLimit,
+    };
+
+    use super::check_shared_constraints;
+
+    const WALLET_ACCESS_ID: i32 = 1;
+    const CHAIN_ID: u64 = 1;
+    const RECIPIENT: Address = address!("1111111111111111111111111111111111111111");
+
+    fn context() -> EvalContext {
+        EvalContext {
+            target: EvmWalletAccess {
+                id: WALLET_ACCESS_ID,
+                wallet_id: 10,
+                client_id: 20,
+                created_at: SqliteTimestamp(Utc::now()),
+            },
+            chain: CHAIN_ID,
+            to: RECIPIENT,
+            value: U256::ZERO,
+            calldata: Bytes::new(),
+            max_fee_per_gas: 100,
+            max_priority_fee_per_gas: 10,
+        }
+    }
+
+    fn shared_settings() -> SharedGrantSettings {
+        SharedGrantSettings {
+            wallet_access_id: WALLET_ACCESS_ID,
+            chain: CHAIN_ID,
+            valid_from: None,
+            valid_until: None,
+            max_gas_fee_per_gas: None,
+            max_priority_fee_per_gas: None,
+            rate_limit: None,
+        }
+    }
+
+    async fn insert_basic_grant(
+        conn: &mut DatabaseConnection,
+        shared: &SharedGrantSettings,
+    ) -> EvmBasicGrant {
+        insert_into(evm_basic_grant::table)
+            .values(NewEvmBasicGrant {
+                wallet_access_id: shared.wallet_access_id,
+                chain_id: shared.chain as i32,
+                valid_from: shared.valid_from.map(SqliteTimestamp),
+                valid_until: shared.valid_until.map(SqliteTimestamp),
+                max_gas_fee_per_gas: shared
+                    .max_gas_fee_per_gas
+                    .map(|fee| super::utils::u256_to_bytes(fee).to_vec()),
+                max_priority_fee_per_gas: shared
+                    .max_priority_fee_per_gas
+                    .map(|fee| super::utils::u256_to_bytes(fee).to_vec()),
+                rate_limit_count: shared.rate_limit.as_ref().map(|limit| limit.count as i32),
+                rate_limit_window_secs: shared
+                    .rate_limit
+                    .as_ref()
+                    .map(|limit| limit.window.num_seconds() as i32),
+                revoked_at: None,
+            })
+            .returning(EvmBasicGrant::as_select())
+            .get_result(conn)
+            .await
+            .unwrap()
+    }
+
+    #[rstest]
+    #[case::matching_chain(CHAIN_ID, false)]
+    #[case::mismatching_chain(CHAIN_ID + 1, true)]
+    #[tokio::test]
+    async fn check_shared_constraints_enforces_chain_id(
+        #[case] context_chain: u64,
+        #[case] expect_mismatch: bool,
+    ) {
+        let db = db::create_test_pool().await;
+        let mut conn = db.get().await.unwrap();
+
+        let context = EvalContext {
+            chain: context_chain,
+            ..context()
+        };
+
+        let violations = check_shared_constraints(&context, &shared_settings(), 999, &mut *conn)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            violations
+                .iter()
+                .any(|violation| matches!(violation, EvalViolation::MismatchingChainId { .. })),
+            expect_mismatch
+        );
+
+        if expect_mismatch {
+            assert_eq!(violations.len(), 1);
+        } else {
+            assert!(violations.is_empty());
+        }
+    }
+
+    #[rstest]
+    #[case::valid_from_in_bounds(Some(Utc::now() - Duration::hours(1)), None, false)]
+    #[case::valid_from_out_of_bounds(Some(Utc::now() + Duration::hours(1)), None, true)]
+    #[case::valid_until_in_bounds(None, Some(Utc::now() + Duration::hours(1)), false)]
+    #[case::valid_until_out_of_bounds(None, Some(Utc::now() - Duration::hours(1)), true)]
+    #[tokio::test]
+    async fn check_shared_constraints_enforces_validity_window(
+        #[case] valid_from: Option<chrono::DateTime<Utc>>,
+        #[case] valid_until: Option<chrono::DateTime<Utc>>,
+        #[case] expect_invalid_time: bool,
+    ) {
+        let db = db::create_test_pool().await;
+        let mut conn = db.get().await.unwrap();
+
+        let shared = SharedGrantSettings {
+            valid_from,
+            valid_until,
+            ..shared_settings()
+        };
+
+        let violations = check_shared_constraints(&context(), &shared, 999, &mut *conn)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            violations
+                .iter()
+                .any(|violation| matches!(violation, EvalViolation::InvalidTime)),
+            expect_invalid_time
+        );
+
+        if expect_invalid_time {
+            assert_eq!(violations.len(), 1);
+        } else {
+            assert!(violations.is_empty());
+        }
+    }
+
+    #[rstest]
+    #[case::max_fee_within_limit(Some(U256::from(100u64)), None, 100, 10, false)]
+    #[case::max_fee_exceeded(Some(U256::from(99u64)), None, 100, 10, true)]
+    #[case::priority_fee_within_limit(None, Some(U256::from(10u64)), 100, 10, false)]
+    #[case::priority_fee_exceeded(None, Some(U256::from(9u64)), 100, 10, true)]
+    #[tokio::test]
+    async fn check_shared_constraints_enforces_gas_fee_caps(
+        #[case] max_gas_fee_per_gas: Option<U256>,
+        #[case] max_priority_fee_per_gas: Option<U256>,
+        #[case] actual_max_fee_per_gas: u128,
+        #[case] actual_max_priority_fee_per_gas: u128,
+        #[case] expect_gas_limit_violation: bool,
+    ) {
+        let db = db::create_test_pool().await;
+        let mut conn = db.get().await.unwrap();
+
+        let context = EvalContext {
+            max_fee_per_gas: actual_max_fee_per_gas,
+            max_priority_fee_per_gas: actual_max_priority_fee_per_gas,
+            ..context()
+        };
+
+        let shared = SharedGrantSettings {
+            max_gas_fee_per_gas,
+            max_priority_fee_per_gas,
+            ..shared_settings()
+        };
+        let violations = check_shared_constraints(&context, &shared, 999, &mut *conn)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            violations
+                .iter()
+                .any(|violation| matches!(violation, EvalViolation::GasLimitExceeded { .. })),
+            expect_gas_limit_violation
+        );
+
+        if expect_gas_limit_violation {
+            assert_eq!(violations.len(), 1);
+        } else {
+            assert!(violations.is_empty());
+        }
+    }
+
+    #[rstest]
+    #[case::under_rate_limit(2, false)]
+    #[case::at_rate_limit(1, true)]
+    #[tokio::test]
+    async fn check_shared_constraints_enforces_rate_limit(
+        #[case] rate_limit_count: u32,
+        #[case] expect_rate_limit_violation: bool,
+    ) {
+        let db = db::create_test_pool().await;
+        let mut conn = db.get().await.unwrap();
+
+        let shared = SharedGrantSettings {
+            rate_limit: Some(TransactionRateLimit {
+                count: rate_limit_count,
+                window: Duration::hours(1),
+            }),
+            ..shared_settings()
+        };
+
+        let basic_grant = insert_basic_grant(&mut conn, &shared).await;
+
+        insert_into(evm_transaction_log::table)
+            .values(NewEvmTransactionLog {
+                grant_id: basic_grant.id,
+                wallet_access_id: WALLET_ACCESS_ID,
+                chain_id: CHAIN_ID as i32,
+                eth_value: super::utils::u256_to_bytes(U256::ZERO).to_vec(),
+                signed_at: SqliteTimestamp(Utc::now()),
+            })
+            .execute(&mut *conn)
+            .await
+            .unwrap();
+
+        let violations = check_shared_constraints(&context(), &shared, basic_grant.id, &mut *conn)
+            .await
+            .unwrap();
+
+        assert_eq!(
+            violations
+                .iter()
+                .any(|violation| matches!(violation, EvalViolation::RateLimitExceeded)),
+            expect_rate_limit_violation
+        );
+
+        if expect_rate_limit_violation {
+            assert_eq!(violations.len(), 1);
+        } else {
+            assert!(violations.is_empty());
+        }
+    }
+}
--- a/server/crates/arbiter-server/src/evm/policies.rs
+++ b/server/crates/arbiter-server/src/evm/policies.rs
@@ -7,11 +7,12 @@ use diesel::{
 };
 use diesel_async::{AsyncConnection, RunQueryDsl};

-use serde::Serialize;
 use thiserror::Error;

 use crate::{
-    crypto::integrity::v1::Integrable, db::models::{self, EvmBasicGrant, EvmWalletAccess}, evm::utils
+    crypto::integrity::v1::Integrable,
+    db::models::{self, EvmBasicGrant, EvmWalletAccess},
+    evm::utils,
 };

 pub mod ether_transfer;
@@ -55,11 +56,14 @@ pub enum EvalViolation {

    #[error("Transaction type is not allowed by this grant")]
    InvalidTransactionType,
+
+    #[error("Mismatching chain ID")]
+    MismatchingChainId { expected: ChainId, actual: ChainId },
 }

 pub type DatabaseID = i32;

-#[derive(Debug, Serialize)]
+#[derive(Debug)]
 pub struct Grant<PolicySettings> {
    pub id: DatabaseID,
    pub common_settings_id: DatabaseID, // ID of the basic grant for shared-logic checks like rate limits and validity periods
@@ -123,19 +127,19 @@ pub enum SpecificMeaning {
    TokenTransfer(token_transfers::Meaning),
 }

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

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

-#[derive(Clone, Debug, PartialEq, Eq, Hash, Serialize)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct SharedGrantSettings {
    pub wallet_access_id: i32,
    pub chain: ChainId,
@@ -196,7 +200,7 @@ pub enum SpecificGrant {
    TokenTransfer(token_transfers::Settings),
 }

-#[derive(Debug, Serialize)]
+#[derive(Debug, Clone)]
 pub struct CombinedSettings<PolicyGrant> {
    pub shared: SharedGrantSettings,
    pub specific: PolicyGrant,
@@ -216,3 +220,37 @@ impl<P: Integrable> Integrable for CombinedSettings<P> {
    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, serde::Serialize)]
+#[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
@@ -84,8 +84,6 @@ fn shared() -> SharedGrantSettings {
    }
 }

-// ── analyze ─────────────────────────────────────────────────────────────
-
 #[test]
 fn analyze_matches_empty_calldata() {
    let m = EtherTransfer::analyze(&ctx(ALLOWED, U256::from(1_000u64))).unwrap();
@@ -102,8 +100,6 @@ fn analyze_rejects_nonempty_calldata() {
    assert!(EtherTransfer::analyze(&context).is_none());
 }

-// ── evaluate ────────────────────────────────────────────────────────────
-
 #[tokio::test]
 async fn evaluate_passes_for_allowed_target() {
    let db = db::create_test_pool().await;
@@ -276,8 +272,6 @@ async fn evaluate_passes_at_exactly_volume_limit() {
    );
 }

-// ── try_find_grant ───────────────────────────────────────────────────────
-
 #[tokio::test]
 async fn try_find_grant_roundtrip() {
    let db = db::create_test_pool().await;
@@ -336,7 +330,36 @@ async fn try_find_grant_wrong_target_returns_none() {
    assert!(found.is_none());
 }

-// ── find_all_grants ──────────────────────────────────────────────────────
+proptest::proptest! {
+    #[test]
+    fn target_order_does_not_affect_hash(
+        raw_addrs in proptest::collection::vec(proptest::prelude::any::<[u8; 20]>(), 0..8),
+        seed in proptest::prelude::any::<u64>(),
+        max_volume in proptest::prelude::any::<u64>(),
+        window_secs in 1i64..=86400,
+    ) {
+        use rand::{SeedableRng, seq::SliceRandom};
+        use sha2::Digest;
+        use crate::crypto::integrity::hashing::Hashable;
+
+        let addrs: Vec<Address> = raw_addrs.iter().map(|b| Address::from(*b)).collect();
+        let mut shuffled = addrs.clone();
+        shuffled.shuffle(&mut rand::rngs::StdRng::seed_from_u64(seed));
+
+        let limit = VolumeRateLimit {
+            max_volume: U256::from(max_volume),
+            window: Duration::seconds(window_secs),
+        };
+
+        let mut h1 = sha2::Sha256::new();
+        Settings { target: addrs, limit: limit.clone() }.hash(&mut h1);
+
+        let mut h2 = sha2::Sha256::new();
+        Settings { target: shuffled, limit }.hash(&mut h2);
+
+        proptest::prop_assert_eq!(h1.finalize(), h2.finalize());
+    }
+}

 #[tokio::test]
 async fn find_all_grants_empty_db() {
--- a/server/crates/arbiter-server/src/evm/policies/token_transfers/mod.rs
+++ b/server/crates/arbiter-server/src/evm/policies/token_transfers/mod.rs
@@ -1,17 +1,5 @@
 use std::collections::HashMap;

-use alloy::{
-    primitives::{Address, U256},
-    sol_types::SolCall,
-};
-use arbiter_tokens_registry::evm::nonfungible::{self, TokenInfo};
-use chrono::{DateTime, Duration, Utc};
-use diesel::dsl::{auto_type, insert_into};
-use diesel::sqlite::Sqlite;
-use diesel::{ExpressionMethods, prelude::*};
-use diesel_async::{AsyncConnection, RunQueryDsl};
-use serde::Serialize;
-
 use crate::db::schema::{
    evm_basic_grant, evm_token_transfer_grant, evm_token_transfer_log,
    evm_token_transfer_volume_limit,
@@ -32,6 +20,16 @@ use crate::{
    },
    evm::policies::CombinedSettings,
 };
+use alloy::{
+    primitives::{Address, U256},
+    sol_types::SolCall,
+};
+use arbiter_tokens_registry::evm::nonfungible::{self, TokenInfo};
+use chrono::{DateTime, Duration, Utc};
+use diesel::dsl::{auto_type, insert_into};
+use diesel::sqlite::Sqlite;
+use diesel::{ExpressionMethods, prelude::*};
+use diesel_async::{AsyncConnection, RunQueryDsl};

 use super::{DatabaseID, EvalContext, EvalViolation};

@@ -64,7 +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, Serialize)]
+#[derive(Debug, Clone)]
 pub struct Settings {
    pub token_contract: Address,
    pub target: Option<Address>,
@@ -73,6 +71,17 @@ pub struct Settings {
 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)
@@ -277,18 +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
@@ -101,8 +101,6 @@ fn shared() -> SharedGrantSettings {
    }
 }

-// ── analyze ─────────────────────────────────────────────────────────────
-
 #[test]
 fn analyze_known_token_valid_calldata() {
    let calldata = transfer_calldata(RECIPIENT, U256::from(100u64));
@@ -128,8 +126,6 @@ fn analyze_empty_calldata_returns_none() {
    assert!(TokenTransfer::analyze(&ctx(DAI, Bytes::new())).is_none());
 }

-// ── evaluate ────────────────────────────────────────────────────────────
-
 #[tokio::test]
 async fn evaluate_rejects_nonzero_eth_value() {
    let db = db::create_test_pool().await;
@@ -412,7 +408,39 @@ async fn try_find_grant_unknown_token_returns_none() {
    assert!(found.is_none());
 }

-// ── find_all_grants ──────────────────────────────────────────────────────
+proptest::proptest! {
+    #[test]
+    fn volume_limits_order_does_not_affect_hash(
+        raw_limits in proptest::collection::vec(
+            (proptest::prelude::any::<u64>(), 1i64..=86400),
+            0..8,
+        ),
+        seed in proptest::prelude::any::<u64>(),
+    ) {
+        use rand::{SeedableRng, seq::SliceRandom};
+        use sha2::Digest;
+        use crate::crypto::integrity::hashing::Hashable;
+
+        let limits: Vec<VolumeRateLimit> = raw_limits
+            .iter()
+            .map(|(max_vol, window_secs)| VolumeRateLimit {
+                max_volume: U256::from(*max_vol),
+                window: Duration::seconds(*window_secs),
+            })
+            .collect();
+
+        let mut shuffled = limits.clone();
+        shuffled.shuffle(&mut rand::rngs::StdRng::seed_from_u64(seed));
+
+        let mut h1 = sha2::Sha256::new();
+        Settings { token_contract: DAI, target: None, volume_limits: limits }.hash(&mut h1);
+
+        let mut h2 = sha2::Sha256::new();
+        Settings { token_contract: DAI, target: None, volume_limits: shuffled }.hash(&mut h2);
+
+        proptest::prop_assert_eq!(h1.finalize(), h2.finalize());
+    }
+}

 #[tokio::test]
 async fn find_all_grants_empty_db() {
--- a/server/crates/arbiter-server/src/grpc/client/auth.rs
+++ b/server/crates/arbiter-server/src/grpc/client/auth.rs
@@ -68,6 +68,7 @@ impl<'a> AuthTransportAdapter<'a> {
                auth::Error::ApproveError(auth::ApproveError::Internal)
                | auth::Error::DatabasePoolUnavailable
                | auth::Error::DatabaseOperationFailed
+                | auth::Error::IntegrityCheckFailed
                | auth::Error::Transport => ProtoAuthResult::Internal,
            }
            .into(),
--- a/server/crates/arbiter-server/src/grpc/common/outbound.rs
+++ b/server/crates/arbiter-server/src/grpc/common/outbound.rs
@@ -8,7 +8,7 @@ use arbiter_proto::proto::{
        EvalViolation as ProtoEvalViolation, GasLimitExceededViolation, NoMatchingGrantError,
        PolicyViolationsError, SpecificMeaning as ProtoSpecificMeaning,
        TokenInfo as ProtoTokenInfo, TransactionEvalError as ProtoTransactionEvalError,
-        eval_violation::Kind as ProtoEvalViolationKind,
+        eval_violation as proto_eval_violation, eval_violation::Kind as ProtoEvalViolationKind,
        specific_meaning::Meaning as ProtoSpecificMeaningKind,
        transaction_eval_error::Kind as ProtoTransactionEvalErrorKind,
    },
@@ -79,6 +79,12 @@ impl Convert for EvalViolation {
            EvalViolation::InvalidTransactionType => {
                ProtoEvalViolationKind::InvalidTransactionType(())
            }
+            EvalViolation::MismatchingChainId { expected, actual } => {
+                ProtoEvalViolationKind::ChainIdMismatch(proto_eval_violation::ChainIdMismatch {
+                    expected,
+                    actual,
+                })
+            }
        };

        ProtoEvalViolation { kind: Some(kind) }
@@ -108,7 +114,7 @@ impl Convert for VetError {
                        violations: violations.into_iter().map(Convert::convert).collect(),
                    })
                }
-                PolicyError::Database(_)| PolicyError::Integrity(_) => {
+                PolicyError::Database(_) | PolicyError::Integrity(_) => {
                    return EvmSignTransactionResult::Error(ProtoEvmError::Internal.into());
                }
            },
--- 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/main.rs
+++ b/server/crates/arbiter-server/src/main.rs
@@ -10,6 +10,7 @@ use tracing::info;
 const PORT: u16 = 50051;

 #[tokio::main]
+#[mutants::skip]
 async fn main() -> anyhow::Result<()> {
    aws_lc_rs::default_provider().install_default().unwrap();

--- a/server/crates/arbiter-server/tests/client/auth.rs
+++ b/server/crates/arbiter-server/tests/client/auth.rs
@@ -1,9 +1,14 @@
 use arbiter_proto::ClientMetadata;
 use arbiter_proto::transport::{Receiver, Sender};
-use arbiter_server::actors::GlobalActors;
 use arbiter_server::{
-    actors::client::{ClientConnection, auth, connect_client},
-    db,
+    actors::{
+        GlobalActors,
+        client::{ClientConnection, ClientCredentials, auth, connect_client},
+        keyholder::Bootstrap,
+    },
+    crypto::integrity,
+    db::{self, schema},
+    safe_cell::{SafeCell, SafeCellHandle as _},
 };
 use diesel::{ExpressionMethods as _, NullableExpressionMethods as _, QueryDsl as _, insert_into};
 use diesel_async::RunQueryDsl;
@@ -21,7 +26,8 @@ fn metadata(name: &str, description: Option<&str>, version: Option<&str>) -> Cli

 async fn insert_registered_client(
    db: &db::DatabasePool,
-    pubkey: Vec<u8>,
+    actors: &GlobalActors,
+    pubkey: ed25519_dalek::VerifyingKey,
    metadata: &ClientMetadata,
 ) {
    use arbiter_server::db::schema::{client_metadata, program_client};
@@ -37,23 +43,64 @@ async fn insert_registered_client(
        .get_result(&mut conn)
        .await
        .unwrap();
-    insert_into(program_client::table)
+    let client_id: i32 = insert_into(program_client::table)
        .values((
-            program_client::public_key.eq(pubkey),
+            program_client::public_key.eq(pubkey.to_bytes().to_vec()),
            program_client::metadata_id.eq(metadata_id),
        ))
+        .returning(program_client::id)
+        .get_result(&mut conn)
+        .await
+        .unwrap();
+
+    integrity::sign_entity(
+        &mut conn,
+        &actors.key_holder,
+        &ClientCredentials { pubkey, nonce: 1 },
+        client_id,
+    )
+    .await
+    .unwrap();
+}
+
+async fn insert_bootstrap_sentinel_useragent(db: &db::DatabasePool) {
+    let mut conn = db.get().await.unwrap();
+    let sentinel_key = ed25519_dalek::SigningKey::generate(&mut rand::rng())
+        .verifying_key()
+        .to_bytes()
+        .to_vec();
+
+    insert_into(schema::useragent_client::table)
+        .values((
+            schema::useragent_client::public_key.eq(sentinel_key),
+            schema::useragent_client::key_type.eq(1i32),
+        ))
        .execute(&mut conn)
        .await
        .unwrap();
 }

+async fn spawn_test_actors(db: &db::DatabasePool) -> GlobalActors {
+    insert_bootstrap_sentinel_useragent(db).await;
+
+    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    actors
+        .key_holder
+        .ask(Bootstrap {
+            seal_key_raw: SafeCell::new(b"test-seal-key".to_vec()),
+        })
+        .await
+        .unwrap();
+    actors
+}
+
 #[tokio::test]
 #[test_log::test]
 pub async fn test_unregistered_pubkey_rejected() {
    let db = db::create_test_pool().await;

    let (server_transport, mut test_transport) = ChannelTransport::new();
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
+    let actors = spawn_test_actors(&db).await;
    let props = ClientConnection::new(db.clone(), actors);
    let task = tokio::spawn(async move {
        let mut server_transport = server_transport;
@@ -78,20 +125,19 @@ pub async fn test_unregistered_pubkey_rejected() {
 #[test_log::test]
 pub async fn test_challenge_auth() {
    let db = db::create_test_pool().await;
+    let actors = spawn_test_actors(&db).await;

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

    insert_registered_client(
        &db,
-        pubkey_bytes.clone(),
+        &actors,
+        new_key.verifying_key(),
        &metadata("client", Some("desc"), Some("1.0.0")),
    )
    .await;

    let (server_transport, mut test_transport) = ChannelTransport::new();
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-
    let props = ClientConnection::new(db.clone(), actors);
    let task = tokio::spawn(async move {
        let mut server_transport = server_transport;
@@ -147,34 +193,13 @@ pub async fn test_challenge_auth() {
 #[test_log::test]
 pub async fn test_metadata_unchanged_does_not_append_history() {
    let db = db::create_test_pool().await;
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-    let props = ClientConnection::new(db.clone(), actors);
-
+    let actors = spawn_test_actors(&db).await;
    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());
    let requested = metadata("client", Some("desc"), Some("1.0.0"));

-    {
-        use arbiter_server::db::schema::{client_metadata, program_client};
-        let mut conn = db.get().await.unwrap();
-        let metadata_id: i32 = insert_into(client_metadata::table)
-            .values((
-                client_metadata::name.eq(&requested.name),
-                client_metadata::description.eq(&requested.description),
-                client_metadata::version.eq(&requested.version),
-            ))
-            .returning(client_metadata::id)
-            .get_result(&mut conn)
-            .await
-            .unwrap();
-        insert_into(program_client::table)
-            .values((
-                program_client::public_key.eq(new_key.verifying_key().to_bytes().to_vec()),
-                program_client::metadata_id.eq(metadata_id),
-            ))
-            .execute(&mut conn)
-            .await
-            .unwrap();
-    }
+    insert_registered_client(&db, &actors, new_key.verifying_key(), &requested).await;
+
+    let props = ClientConnection::new(db.clone(), actors);

    let (server_transport, mut test_transport) = ChannelTransport::new();
    let task = tokio::spawn(async move {
@@ -225,33 +250,18 @@ pub async fn test_metadata_unchanged_does_not_append_history() {
 #[test_log::test]
 pub async fn test_metadata_change_appends_history_and_repoints_binding() {
    let db = db::create_test_pool().await;
-    let actors = GlobalActors::spawn(db.clone()).await.unwrap();
-    let props = ClientConnection::new(db.clone(), actors);
-
+    let actors = spawn_test_actors(&db).await;
    let new_key = ed25519_dalek::SigningKey::generate(&mut rand::rng());

-    {
-        use arbiter_server::db::schema::{client_metadata, program_client};
-        let mut conn = db.get().await.unwrap();
-        let metadata_id: i32 = insert_into(client_metadata::table)
-            .values((
-                client_metadata::name.eq("client"),
-                client_metadata::description.eq(Some("old")),
-                client_metadata::version.eq(Some("1.0.0")),
-            ))
-            .returning(client_metadata::id)
-            .get_result(&mut conn)
-            .await
-            .unwrap();
-        insert_into(program_client::table)
-            .values((
-                program_client::public_key.eq(new_key.verifying_key().to_bytes().to_vec()),
-                program_client::metadata_id.eq(metadata_id),
-            ))
-            .execute(&mut conn)
-            .await
-            .unwrap();
-    }
+    insert_registered_client(
+        &db,
+        &actors,
+        new_key.verifying_key(),
+        &metadata("client", Some("old"), Some("1.0.0")),
+    )
+    .await;
+
+    let props = ClientConnection::new(db.clone(), actors);

    let (server_transport, mut test_transport) = ChannelTransport::new();
    let task = tokio::spawn(async move {
@@ -322,3 +332,59 @@ pub async fn test_metadata_change_appends_history_and_repoints_binding() {
        );
    }
 }
+
+#[tokio::test]
+#[test_log::test]
+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 = ed25519_dalek::SigningKey::generate(&mut rand::rng());
+    let requested = metadata("client", Some("desc"), Some("1.0.0"));
+
+    {
+        use arbiter_server::db::schema::{client_metadata, program_client};
+        let mut conn = db.get().await.unwrap();
+        let metadata_id: i32 = insert_into(client_metadata::table)
+            .values((
+                client_metadata::name.eq(&requested.name),
+                client_metadata::description.eq(&requested.description),
+                client_metadata::version.eq(&requested.version),
+            ))
+            .returning(client_metadata::id)
+            .get_result(&mut conn)
+            .await
+            .unwrap();
+        insert_into(program_client::table)
+            .values((
+                program_client::public_key.eq(new_key.verifying_key().to_bytes().to_vec()),
+                program_client::metadata_id.eq(metadata_id),
+            ))
+            .execute(&mut conn)
+            .await
+            .unwrap();
+    }
+
+    let (server_transport, mut test_transport) = ChannelTransport::new();
+    let props = ClientConnection::new(db.clone(), actors);
+    let task = tokio::spawn(async move {
+        let mut server_transport = server_transport;
+        connect_client(props, &mut server_transport).await;
+    });
+
+    test_transport
+        .send(auth::Inbound::AuthChallengeRequest {
+            pubkey: new_key.verifying_key(),
+            metadata: requested,
+        })
+        .await
+        .unwrap();
+
+    let response = test_transport
+        .recv()
+        .await
+        .expect("should receive auth rejection");
+    assert!(matches!(response, Err(auth::Error::IntegrityCheckFailed)));
+
+    task.await.unwrap();
+}
--- a/server/crates/arbiter-server/tests/user_agent/unseal.rs
+++ b/server/crates/arbiter-server/tests/user_agent/unseal.rs
@@ -11,8 +11,6 @@ use arbiter_server::{
    safe_cell::{SafeCell, SafeCellHandle as _},
 };
 use chacha20poly1305::{AeadInPlace, XChaCha20Poly1305, XNonce, aead::KeyInit};
-use diesel::{ExpressionMethods as _, QueryDsl as _, insert_into};
-use diesel_async::RunQueryDsl;
 use kameo::actor::Spawn as _;
 use x25519_dalek::{EphemeralSecret, PublicKey};
Author	SHA1	Message	Date
CleverWild	763058b014	feat(server): unify integrity API and propagate verified IDs through auth/EVM flows Some checks failed ci/woodpecker/pr/server-audit Pipeline was successful Details ci/woodpecker/pr/server-vet Pipeline failed Details ci/woodpecker/pr/server-lint Pipeline was successful Details ci/woodpecker/pr/server-test Pipeline was successful Details	2026-04-07 21:12:36 +02:00
hdbg	1497884ce6	fix(server::bootsrapper): token compare is now constant-time Some checks failed ci/woodpecker/push/server-audit Pipeline was successful Details ci/woodpecker/push/server-vet Pipeline failed Details ci/woodpecker/push/server-lint Pipeline failed Details ci/woodpecker/push/server-test Pipeline was successful Details	2026-04-06 18:33:47 +02:00
hdbg	b3464cf8a6	tests(server::client::auth): integrity envelope insertion for valid paths Some checks failed ci/woodpecker/pr/server-audit Pipeline was successful Details ci/woodpecker/pr/server-vet Pipeline failed Details ci/woodpecker/pr/server-lint Pipeline failed Details ci/woodpecker/pr/server-test Pipeline was successful Details ci/woodpecker/push/server-audit Pipeline was successful Details ci/woodpecker/push/server-vet Pipeline failed Details ci/woodpecker/push/server-lint Pipeline failed Details ci/woodpecker/push/server-test Pipeline was successful Details	2026-04-06 18:24:13 +02:00
hdbg	46d1318b6f	feat(server): add integrity verification for client keys	2026-04-06 18:13:11 +02:00
Stas	9c80d51d45	Merge pull request 'fix(server): replaced postcard-based integrity fingerprint with custom trait providing order-independent hashing' (#77 ) from push-opwuyuwxknyo into main Some checks failed ci/woodpecker/push/server-audit Pipeline was successful Details ci/woodpecker/push/server-vet Pipeline failed Details ci/woodpecker/push/server-lint Pipeline failed Details ci/woodpecker/push/server-test Pipeline was successful Details Reviewed-on: #77	2026-04-06 15:42:47 +00:00
hdbg	33456a644d	tests(server): property-based testing for ordering independency for hash Some checks failed ci/woodpecker/pr/server-audit Pipeline was successful Details ci/woodpecker/pr/server-lint Pipeline failed Details ci/woodpecker/pr/server-vet Pipeline failed Details ci/woodpecker/pr/server-test Pipeline was successful Details	2026-04-06 17:40:41 +02:00
hdbg	5bc0c42cc7	fix(server): replaced `postcard`-based integrity fingerprint with custom trait providing order-independent hashing	2026-04-06 16:25:32 +02:00
hdbg	f6b62ab884	fix(server): added `chain_id` check and covered `check_shared_constraints` with unit tests Some checks failed ci/woodpecker/pr/server-audit Pipeline was successful Details ci/woodpecker/pr/server-lint Pipeline failed Details ci/woodpecker/pr/server-vet Pipeline failed Details ci/woodpecker/pr/server-test Pipeline was successful Details ci/woodpecker/push/server-audit Pipeline was successful Details ci/woodpecker/push/server-lint Pipeline failed Details ci/woodpecker/push/server-vet Pipeline failed Details ci/woodpecker/push/server-test Pipeline was successful Details	2026-04-06 12:57:18 +02:00
hdbg	2dd5a3f32f	tests(server): initial `cargo-mutants` Some checks failed ci/woodpecker/push/server-audit Pipeline was successful Details ci/woodpecker/push/server-vet Pipeline failed Details ci/woodpecker/push/server-lint Pipeline failed Details ci/woodpecker/push/server-test Pipeline was successful Details	2026-04-06 12:03:56 +02:00
hdbg	1aca9d4007	fix(server): simplify hash function for `debug` profile	2026-04-05 22:50:28 +02:00
Stas	5ee1b49c43	Merge pull request 'feat(server): integrity envelope engine for EVM grants with HMAC verification' (#51 ) from integrity-envelope into main Some checks failed ci/woodpecker/push/server-audit Pipeline was successful Details ci/woodpecker/push/server-lint Pipeline failed Details ci/woodpecker/push/server-vet Pipeline failed Details ci/woodpecker/push/server-test Pipeline was successful Details Reviewed-on: #51	2026-04-05 16:26:51 +00:00