HQC-HAMMING-QUASI-CYCLIC

NIST Round 4 French HQC code-based KEM.

Definition

HQC parameter sets: HQC-128 (Level 1), HQC-192 (Level 3), HQC-256 (Level 5). Sizes: HQC-128 public key 2249 bytes, ciphertext 4481 bytes (larger than Kyber/BIKE). Specificity: DFR = 0 (perfect decoding via concatenated codes), differs from BIKE. Performance: slower KeyGen Encap/Decap vs Kyber, but standalone-secure assumptions on hash functions and code decoding. Potential adoption: cryptographic agility diversification complementing Kyber.

Origin

HQC submitted to NIST PQC Round 1 November 2017 ; advanced to Round 2, 3, 4 ; backup KEM standardisation expected 2024-2025 by NIST.

Example in context

ANSSI considers HQC as PQC diversification option in its French post-quantum cryptographic referential complementing Kyber to hedge against potential attacks.

Related terms

• BIKE — other code-based KEM.