Cryptography and Keys

This document defines the cryptographic expectations for decision packages, audit integrity, and key management.

Decision Package Signatures

• Decision packages MUST include a signatures array with one or more signatures when enforcement requires signed governance.
• Each signature MUST include key_id, algorithm, and signature fields.
• The signature payload MUST be the canonical encoding defined in STANDARD/WIRE_FORMAT.md.
• Implementations MUST verify that the number of valid signatures meets or exceeds the configured threshold.

Key Management

• Implementations MUST support key rotation by key_id without requiring ledger downtime.
• Verification keys MUST be identified by stable key_id values.
• Key material MUST be stored and transmitted using secure channels and access-controlled storage.
• Implementations SHOULD support key revocation or deactivation via governance or operational policy.

Algorithms

• Signature algorithms MUST be referenced by name from the algorithm registry in STANDARD/REGISTRIES.md.
• Implementations SHOULD support ed25519 for interoperability.

Hashing

• If audit or governance logs are hash-chained, the hashing algorithm MUST be named in the hash registry and MUST be collision resistant.
• Implementations SHOULD support sha256.