open-standards/wai/edge-conformance/README.md

edge-conformance — the deriving edge

The corpus of extensions/deriving-edge.md §10, in one file, vectors.json, written from fixed seeds by wai_edge_vectors gen (wai-rs, feature derive_edge). Every key is SHA-256 of a label, every picture a function of its coordinates, every time a constant, and Ed25519 signing is deterministic (RFC 8032).

Provenance. wai_edge_vectors gen (wai-rs, feature derive_edge) writes every file of this corpus, and its only input is the generator's own code: keys from SHA-256 of labels, pictures as functions of their coordinates, constant times. No content comes from outside this repository.

Derivation equivalence. Each vector is what a verifier holds (§7.1) and the outcome §7 gives the record at subject:

• records: record texts, as they were sent;
• receipts: the JWP group and object receipts (jwp-receipts §2.4.1, §2.4.2): the publishers' and each edge's;
• objects: the envelopes held, each under the content hash it was given by, as lowercase hexadecimal; a vector that holds an object altered keeps it under the name it was given;
• sources: the publisher keys the verifier subscribed to;
• heads: for each origin it holds one for, the head revision of that origin's key log;
• claims and c2pa: the provenance it holds (§6.1): claim texts, and C2PA Manifest Stores in hexadecimal by the content hash of the object each is bound to. The corpus's stores are byte strings standing for one: a verifier names a store by its SHA-256 and parses none;
• policy: attested, recompute and authority (§7.1);
• the outcome: refuse with the reason and its place at (§7.2), or accept with the facts of §7.4 — the subject's record hash, each hop in the order first reached with its record hash, signer, derivation, check, how it was checked, its energy, its authority and its AI-origin label, each source object reached, the energy per acquisition class with the number of unmetered hops, and the provenance items the subject's record carries.

A conforming verifier gives every vector the outcome, the reason, the place and the facts it states.

The parties: a publisher whose signer_id names the origin https://source.example, and whose key log there lists edges edge-a and edge-b with edge/derive, edge-c with delivery alone and edge-d revoked; a second publisher whose signer_id is a did:key, so its objects name no origin. The publisher signs, in one group, an integer clip (wai.video.int_motion, three frames of 8 × 6), three stills and a smaller one, a still whose PNG holds an ancillary chunk, a WAI2 envelope of a still and a JPEG picture, a still whose PNG embeds a manifest store in a caBX chunk, with a soft-binding claim about it and a store beside it in the personal compartment, and a still whose provenance says it was generated.

Checks.

• wai_edge_vectors verify edge-conformance and tests/derive_edge.rs: the file regenerates byte for byte and no other file is here but this README and edge_verify.py; wai-rs gives every vector its outcome; every reason of §9 appears; §9 lists exactly the reference's codes and §4 exactly its derivations; and the reference edge, wai_edge, run twice over a clip, makes a chain of two hops that verifies, and that is refused once a byte of it changes.
• python3 -I edge_verify.py . (edge_verify.py, standard library only): the second implementation, written from the extension's text and sharing no code with wai-rs. It re-executes every replicate hop, writing each still itself, requires every vector's outcome, requires every mutated copy of the corpus to fail, and requires the corpus to catch the verifier with each of its own checks dropped in turn.