How verification works

A conformant verifier runs the same sequence everywhere, failing closed at the first failure. It is operator-independent by design — nothing in it is specific to who runs it.

1. Signatures. Verify the two detached signatures — consent (subject / custodian) and issuance (issuer) — over the canonical Grant.
2. Validity window. The Grant must be within nbf…exp.
3. Status. Fetch the signed status list (or a mirror). Expired list ⇒ fail closed. Bit set ⇒ REFUSED_REVOKED.
4. Scope. Requested purpose in purposes, not in exclusions; territory permitted.
5. Lease. Within the lease window and under the spend cap.

Success yields PERMITTED_CONFORMANT; anything else yields the matching REFUSED_*. The executable form of this is reference/h2a_ref/verify.py — the demo issues a signed grant and shows permit, out-of-scope refusal, and post-revocation refusal.