H33 protocols are built for long-term cryptographic reproducibility. Verifier outputs, replay integrity classifications, rejection semantics, domain separators, and compatibility rules are frozen and regression-tested against canonical conformance vectors.
Protocol freeze is a binding commitment. Frozen surfaces cannot change without a major version increment, a migration guide, and a minimum 12-month overlap window.
| Frozen Surface | Description |
|---|---|
| Verifier Schemas | Input/output shapes, field names, types, and ordering for all verifier endpoints |
| Proof Profiles | The 7 canonical proof profile definitions and their parameter envelopes |
| Replay Integrity Semantics | Classification logic, grading thresholds, and replay integrity labels |
| Error Namespaces | All 26 HATS_ERR codes, their severity levels, and requirement references |
| Deterministic Ordering | Field serialization order in transcripts and canonical encodings |
| Domain Separators | All context strings used in hash derivation and transcript binding |
| Canonical Encodings | Byte-level encoding rules for proofs, signatures, and attestation bundles |
| Transcript Semantics | Transcript derivation logic, append ordering, and finalization rules |
Protocol drift immediately breaks CI through canonical freeze vectors and regression corpora.
The same proof always produces identical transcript derivation, identical replay classification, identical rejection semantics, identical verifier outputs. Across implementations. Across languages. Forever.
Malformed governance does not merely fail. It fails deterministically with stable error codes, severity classification, requirement references, and replay integrity grading.
{
"error": "HATS_ERR_POLICY_EXPIRED",
"severity": "critical",
"requirement": "REQ-1.3",
"replay_integrity": "deterministic",
"message": "Governing policy version 4 expired at 2026-05-01T00:00:00Z",
"resolution": "Activate policy version 5 or later",
"verifier_output": {
"transcript_hash": "a3f8c1...",
"rejection_class": "policy_violation",
"deterministic": true
}
}
Protocol evolution follows strict compatibility rules. Some changes are safe within a minor version. Others require a breaking version increment.
| Surface | v1.x Status |
|---|---|
| Field additions | Allowed |
| Field removals | Breaking (v2 required) |
| Error code rename | Forbidden |
| Severity reclassification | Forbidden |
| Requirement ID reuse | Forbidden |
| Domain separator mutation | Forbidden |
| Proof profile additions | Allowed |
| Replay integrity reordering | Breaking (v2 required) |
| New test vectors | Allowed |
| Existing vector modification | Breaking (v2 required) |
Third-party implementations can validate protocol equivalence without trusting H33 infrastructure.
| Implementation | Language | Vectors Passing | Status |
|---|---|---|---|
| H33 Reference | Rust | 26/26 | Conformant |
| Your implementation | — | — | Register below |
Contact standard@h33.ai to register your implementation.
HATS compatibility is not a claim. It is a test result. 26 canonical vectors. Byte-identical expected outputs. Any language.
$ hats-verify conformance path/to/vectors/
H33's STARK engine runs in pure Rust. The cryptographic hot path does not depend on JavaScript or browser runtimes. No scripting layer participates in proving, verification, transcript construction, field arithmetic, challenge derivation, or security-critical execution.
Portable JSON test vectors allow independent verifiers in Go, TypeScript, Python, Java, or Rust to reproduce identical outputs. The proving and verification path is fully deterministic and backed by 524+ passing tests plus 26 canonical conformance vectors for third-party reimplementation.
Download the canonical test vectors. Run the reference verifier. Or build your own. The protocol is the proof.