Security Model

Authentication

• API keys: Hashed with HMAC-SHA256 before storage. Plaintext never persisted.
• Pilot tokens: SHA-256 hashed. Scoped by max jobs, expiry, and allowed lanes.
• Partner API keys: Separate table from core platform keys (anti-contamination).
• Rate limiting: Redis-backed in production (100 req/min per key hash). In-memory for pilot.

Replay protection

Mutating requests (POST, PUT, DELETE) in production postures require:

• X-Nonce header (one-time use, scoped by key hash)
• X-Timestamp header (within configurable window, default ±300s)

Nonces are stored in Redis with TTL matching the timestamp window. Fail-closed: if Redis is unreachable, requests are rejected.

Request signing

Optional per-key policy. When enabled, the X-Signature header must contain a valid HMAC-SHA256 signature over METHOD + PATH + QUERY + TIMESTAMP + NONCE + BODY_HASH. Per-key signing secrets are encrypted at rest.

Encryption at rest

• Database: Cloud SQL with Google-managed encryption (AES-256).
• Uploads: Stored in Cloud Storage with default encryption. Automatic deletion within 24 hours.
• CMEK: Available for Enterprise MMC lanes only.

Key management

• Receipt signing: Ed25519 signing keys are protected by Google Cloud KMS in production. Private keys are not exported.
• JWKS (canonical): Issuer public keys are published at https://registry.attestlayer.com/v1/jwks/issuer.jwks.json. Each kit also includes a jwks.json snapshot for offline verification.
• Key rotation: Enabled in production postures. Old keys remain in JWKS for verification of previously issued receipts.

Posture model

Three postures with escalating security controls: