Changelog

All notable changes to metamorphic_log are documented here. The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[0.1.3]

Supply-chain currency bump. Bumps the wrapped crate dependencies metamorphic-log 0.1.4 -> 0.1.5 and metamorphic-crypto 0.9 -> 0.10 (published crates only; no [patch]/path deps). No canonical byte-format changes — inclusion/consistency, key-history/v1, CONIKS, signed-note/checkpoint, commitment, policy-v1, KEYTRANS, and ingestion are all unchanged. The wrapped metamorphic-crypto 0.10 is additive only (adds a standalone HKDF-SHA512 primitive that is unused here). p256 stays pinned at =0.14.0-rc.14.

[0.1.2]

Brings the NIF up to parity with the metamorphic-log Rust crate 0.1.4, adding the Slice 9 KEYTRANS (IETF combined-tree directory) verification surface and the namespace-policy directory axis. Bumps the wrapped crate dependencies metamorphic-log 0.1.3 -> 0.1.4 and metamorphic-crypto 0.8 -> 0.9 (published crates only; no [patch]/path deps). No canonical byte-format changes to any frozen layer — inclusion/consistency, key-history/v1, CONIKS, signed-note/checkpoint, commitment, policy-v1, and ingestion are all unchanged, and the CONIKS-route policy output is backward-compatible (new keys are additive).

Added

• KEYTRANS verification (MetamorphicLog.Keytrans). Suite-aware, relying-party verification of the IETF KEYTRANS combined-tree directory (draft-ietf-keytrans-protocol-04), mirroring the browser WASM SDK's keytransVerify*Suite surface. Stateless — recomputes everything from public inputs (VRF public key, combined-tree root, label, proof).
  • verify_search/6 — greatest-version search (§6): the value at a label's most recent version, or absence.
  • verify_fixed_version/6 — fixed-version search (§7).
  • verify_monitor/6 — monitoring (§8): a downgrade is rejected.
  • suite_id/1 — the §15.1 suite_id for a suite atom.
  • The cipher suite is always explicit (no default): :kt128_sha256_p256 (0x0001), :kt128_sha256_ed25519 (0x0002) — the on-spec IETF standard suites (HMAC-SHA256 commitment) — and :metamorphic_hybrid_exp (0xF000), the private hybrid-PQ suite.
  • Movable / experimental: the proof wire is tagged KEYTRANS_EXP_04 and tracks the draft; it is deliberately not byte-frozen. The golden test vectors are kept out of the frozen cross-language KAT set.
• Policy directory axis (MetamorphicLog.Policy).

  • Verified policies now expose :directory_mode (:coniks | :keytrans) and :keytrans_suite (:metamorphic_hybrid_exp | :kt128_sha256_p256 | :kt128_sha256_ed25519) alongside the existing posture fields (additive, backward-compatible; default to the CONIKS route).

  • enforce_directory_backend/2 — declared == observed for the directory backend, accepting a :coniks / :keytrans atom or a raw u16 id.

0.1.1

Brings the NIF up to parity with the metamorphic-log Rust crate 0.1.3, adding the Slice 8 anchoring / attestation surface (the crate's first post-v0.1 slice). No canonical byte-format changes to any audited layer; the existing verification, CONIKS, policy, and ingestion surfaces are unchanged. Bumps the wrapped crate dependency 0.1.2 -> 0.1.3.

Added

• Backend-agnostic anchoring (MetamorphicLog.Anchor). Format + verification for committing a checkpoint's signed tree head to an external, hard-to-equivocate medium (chain, RFC 3161 notary, WORM storage, another log), byte-identical to the native core and WASM SDK. Deliberately I/O-free — the medium client, cadence, fees, and confirmation depth stay in the operator layer.
  • record_canonical_bytes/6 / parse_record/1 — the canonical, byte-locked AnchorRecord binding a checkpoint head (origin / size / root_hash) to an opaque locator and an agnostic medium tag, with a self-describing safe-menu commitment algorithm ("sha3_512" in v0.1).
  • anchor_commitment/1 — the fixed-size, medium-independent commitment an operator publishes to (and re-fetches from) the medium.
  • rfc6962_leaf_hash/1 — the record's Layer-0 leaf hash, so attestations may themselves be logged.
  • verify_anchored/4 — the log-side third-party audit that an attestation binds a checkpoint and that successive anchored heads are append-only consistent (RFC 9162), trusting neither operator nor medium.
  • verify_commitment/2 — the medium-side counterpart: bytes fetched from the medium equal the recomputed commitment. The Rust CommitmentSink trait and its I/O bridges are intentionally not wrapped — that backend belongs on the BEAM side.
• Docs: HexDocs badge in the README and an Anchoring module group.

0.1.0

Initial release: the Elixir/Hex client for the metamorphic-log transparency-log engine, as a sibling package to metamorphic_crypto, built on precompiled Rust NIFs (Rustler + rustler_precompiled) wrapping the published metamorphic-log crate.

Added

• Verification + monitor SDK, mirroring the browser WASM SDK surface:
  • MetamorphicLog.Proof — RFC 6962/9162 inclusion & consistency verification.
  • MetamorphicLog.Checkpoint / MetamorphicLog.Note — C2SP signed-note and tlog-checkpoint parse/verify, with classical Ed25519 and additive hybrid post-quantum (ML-DSA + Ed25519) signatures.
  • MetamorphicLog.Coniks / MetamorphicLog.Commitment — CONIKS lookup/absence proof verification and SHA3-512 commitment verification.
  • MetamorphicLog.Policy — signed namespace-policy verification and declared == observed posture enforcement.
  • MetamorphicLog.Leaf — the mosslet/key-history/v1 canonical leaf encoding, entry hash, and RFC 6962 leaf hash.
• Ingestion primitives (MetamorphicLog.Ingest) — content/token dedup keys, tile flush geometry, and Merkle recomputation over tile bytes for an Elixir operator pipeline. Sequencing state and tile I/O are intentionally left to the BEAM side.
• CPU-bound NIFs (proof/VRF/signature verification, Merkle recomputation) run on dirty CPU schedulers; micro-operations run inline.
• Cross-language byte-parity KAT (test/cross_language_kat_test.exs): the NIF reproduces the same locked vectors as the Rust core and WASM SDK (metamorphic-log/tests/cross_language.rs).