Architecture

The implementation separates untrusted bytes, bounded witness construction, cryptographic verification, and application policy. This separation is part of the security boundary: native parsing is never an acceptance path by itself.

Layers

Layer	Responsibility	Does not decide
Native parser and codec	Decode canonical, bounded request and envelope shapes; construct witnesses	Whether a presentation is accepted
Relation layer	Constrain issuer signature, disclosures, claim policy, holder binding, and optional revocation	Issuer governance or authorization
VerifyRelation	Verify the selected cryptographic relation and identity	Replay consumption or application policy
VerifyPresentation	Add typed local policy and an application-owned replay store	The caller's final authorization decision
CLI	Adapt protected files to the public APIs	Authority from proof-supplied trust material

Fail-closed dispatch

Typed builders construct only the supported exact-key bearer and holder-bound identities. Version, binding mode, trust mode, capacity, digest, field, rate, and query parameters are part of the accepted circuit identity. Malformed, reordered, substituted, or unsupported envelopes reject before proof dispatch.

Trust flows inward

The relying party supplies the exact issuer key and, when required, the trusted revocation-list snapshot. Neither value is accepted from the presentation. The request transcript binds this policy with audience, purpose, nonce, time, claim policy, and the selected circuit identity.

Source map

• include/sd_jwt_zk/presentation.h — supported product-facing API.
• src/presentation.cc — typed request and presentation verification.
• src/bounded_json.cc and src/restricted_json.cc — bounded native parsing.
• src/flat_bearer_proof.cc and src/holder_bound_proof.cc — shipped proof families.
• src/status_membership.cc — optional revocation component.

Continue with the protocol journey or inspect the release-assurance boundary.