Module verifiable_credential 

Verifiable Credentials — native issue / verify core (#19).

A credential = an ISSUER (an agent), a SUBJECT (an agent), a set of claim quins, and a validity window, sealed with an Ed25519 signature over a canonical SHA-256 digest of those fields. This is the NATIVE proof (fast, fits the engine); a W3C JSON-LD Data Integrity export is future work, and the lineage is the W3C Verifiable Claims WG.

Two principles are enforced here:

• Verification authenticates ORIGIN, not TRUTH (principle-identifiers-not-identity): a valid signature proves who said it, not that the claim is true. A verified VC still enters the frame-relative machinery; it is never auto-promoted to fact.
• Grounded issuers (agency.n3 G1’, via agent.rs): a credential whose issuer is an ArtificialAgent with no Principal is rejected by verify_grounded — an AI agent cannot issue free-floating credentials with no human accountable behind it.

Structs

Credential

A credential: who attests, about whom, what, and for how long.

Enums

VcError

Functions

decode_credential

Deserialize a Credential from binary format.

encode_credential

Serialize a Credential to binary format.

issue

Issue: seal the credential with the issuer’s Ed25519 signing key.

verify

Verify the signature + expiry. Authenticates the claim’s ORIGIN (who issued it) and that it has not lapsed — NOT that the claim is true.

verify_grounded

Verify as verify, and additionally reject the credential if its issuer is an ungrounded artificial agent in index (agency.n3 G1’ — no human Principal behind it).