# Security Model

## Threat model

The threat model covers actor impersonation, key compromise, replay, scope widening, validator collusion, gateway compromise, side-channel disclosure, and revocation evasion. Mitigations are tracked in `governance/threat_matrix.md` in the public repository.

## Cryptographic primitives

ML-DSA-65 (CRYSTALS-Dilithium) for signatures, with hybrid signature support. Hashing primitives and AEAD selections track current best practice and are documented in the security crate.

## Determinism

No floating-point arithmetic anywhere in the protocol. Validation and consensus paths are deterministic so that disputes can be re-played bit-for-bit.

## Disclosure

See the public [security page](/content/security/index.html) for coordinated-disclosure contact and PGP key.