lib-q-double-kem 0.0.6

PROVISIONAL double ML-KEM-768 encapsulation profile with constrained wire budget
Documentation

lib-q-double-kem (PROVISIONAL)

lib-q-double-kem provides a provisional MAUL v1 profile for combining two ML-KEM-768 encapsulation lanes into a single upgraded shared secret.

Status

  • Provisional research profile for Hint-MLWE style wire-constrained transport.
  • The API and wire layout can evolve before standardization.

Proof size table

Measured from tests/vectors/manifest.json (KAT seed, MAUL v1 encap path):

Scenario Bytes Budget Pass
Baseline (2× ML-KEM-768) 2176 — —
MAUL v1 wire (double_kem encap) 1260 1260 yes
Size savings vs baseline 42.1% ≥40% yes

Fixed wire split: hint 172 B + body 1088 B = 1260 B.

KAT export

Schema: double-kem-kat-v1

cargo test -p lib-q-double-kem kat_regenerate_vectors -- --ignored

Output: tests/vectors/double-kem-v1.json

Core API

  • MaulProfileV1
  • double_encap
  • double_decap
  • ck_fo_upgrade

Shared secret derivation

The final shared secret is derived as:

ss = KDF(ss_a || ss_b)

with a domain-separated SHA3-256 based KDF.

Security notes

  • This profile is intended for controlled environments and deterministic testability.
  • Production integrations must review threat model fit, replay constraints, and profile governance.