Independent implementation challenge: VAP Evidence Pack verifier

[veritaschain]

Objective

Produce the first organizationally independent implementation of the VAP Common Evidence Pack interoperability contract introduced in PR #1.

The implementation must be maintained outside the veritaschain GitHub organization and written without copying or mechanically translating either VSO reference verifier.

Required behavior

Using the vectors produced by interop/vap-evidence-pack-demo/generate_demo.py at the merged commit, the implementation must return:

Vector	Required result
valid-pack.json	PASS
invalid-tampered-event.json	FAIL
invalid-omitted-outcome.json	FAIL due to Completeness Invariant
invalid-split-view.json	FAIL due to cross-party root disagreement

Mandatory checks

• Ed25519 signatures
• payload hashes
• event identifier uniqueness
• contiguous sequence numbers
• RFC 6962-style domain-separated Merkle root
• signed scope commitment
• producer/observer/external receipt agreement
• event-count agreement
• ATTEMPT_OUTCOME_BIJECTION completeness rule

Independence criteria

• repository is outside the VeritasChain organization;
• no import, copied source, or mechanical translation of the Python/Node reference code;
• implementation algorithm is documented;
• source is publicly reviewable under an OSI-approved license;
• submission states language, toolchain, platform, commit SHA, vectors commit SHA, and execution results;
• ambiguities or disagreements with the contract are reported publicly.

Preferred languages

Rust, Go, Java, C#, or another implementation ecosystem not used by the reference verifiers.

Submission template

implementation_name: example-vap-verifier
repository: https://github.com/example/example-vap-verifier
commit: <40-character SHA>
language: Rust 1.xx
platform: Linux x86_64
vectors_commit: <vap-spec commit SHA>
results:
  valid-pack.json: PASS
  invalid-tampered-event.json: FAIL
  invalid-omitted-outcome.json: FAIL
  invalid-split-view.json: FAIL
code_reuse_from_vso_reference: false

Successful completion establishes public interoperability evidence. It is not certification, regulatory approval, or VSO endorsement.