Offline Verifier Trust Model

The HELM Offline Verifier is a standalone tool designed for high-assurance audits and air-gapped verification of EvidencePacks.

Trust Assumptions

1. Cryptographic Primitives: The verifier trusts the mathematical correctness of Ed25519 signatures, SHA-256 hashes, and JCS (RFC 8785) canonicalization.
2. Standard Compliance: The verifier assumes the EvidencePack format adheres to the UCS v1.2 specification.
3. No Network Trust: The verifier does NOT require network access and does NOT trust results from the HELM server or any proxy.

Verification Layers

1. Structural Integrity: Ensures the bundle contains required indices and manifests.
2. Content Integrity: Verifies that every file matches its hash in the signed manifest.
3. Chain Integrity: Validates the causal DAG (ProofGraph) and prevents reordering or deletion of events.
4. Temporal Integrity: Checks Lamport clock monotonicity across the event stream.
5. Policy Binding: Recomputes policy hashes to ensure the Kernel applied the correct rules.

Auditor Mode

Using the --json flag, the verifier produces a machine-readable report containing every check performed, suitable for inclusion in formal compliance artifacts.