affinidi_tsp_pq 0.1.1

Post-quantum key types for affinidi_tsp: the MLKEM768-X25519 hybrid HPKE KEM (0x647a) and ML-DSA-65 signatures, on the pure-Dart pqcrypto package.

affinidi_tsp_pq

Post-quantum key types for affinidi_tsp:

• MlKem768X25519EncryptionKey / MlKem768X25519DecryptionKey — the MLKEM768-X25519 hybrid HPKE KEM (0x647a, the X-Wing construction as pinned by draft-ietf-hpke-pq). The private key is the 32-byte seed.
• MlDsa65SigningKey (4032-byte expanded key, deterministic signing, empty context) / MlDsa65VerificationKey (1952 bytes).
• PostQuantumKeyMapper for SsiVidResolver, recognising the provisional private-use multicodecs the ToIP reference writes into did:peer:4 documents (0x300001 ML-DSA-65, 0x300000 MLKEM768-X25519).

TSP Rev 3 post-quantum support is HPKE-Base with the KEM selected by the receiver's key type and the signature scheme by the sender's, so these keys go straight into PrivateVid/PublicVid and the usual Tsp.pack/Tsp.open.

ML-KEM-768 and ML-DSA-65 come from pqcrypto (pure Dart, zero dependencies, KAT-verified against the NIST FIPS 203/204 corpora), which ssi 4.x already depends on. It requires Dart 3.10, which is why this is a separate package from affinidi_tsp (Dart 3.8).

Verified by dart test: the draft-ietf-hpke-pq MLKEM768-X25519 / HKDF-SHA256 / ChaCha20Poly1305 vector (DeriveKeyPair, Encap with fixed randomness, Decap, key schedule, first encryption) and opening the TSP Appendix A direct-hpke-base-pq vector.

Note: 1AAQ (the ML-DSA-65 signature code) is provisional in the specification, pending CESR registration.