HQC-128 Security API

Version: 1.0.0
Last Updated: 2025-01-02
Security Classification: Code-Based KEM
Author: MetaMUI Security Team

Overview

HQC (Hamming Quasi-Cyclic) is a code-based KEM using quasi-cyclic codes, providing an alternative to lattice-based schemes.

• Algorithm Family: Code-based KEM
• Security Level: NIST Level 1 (128-bit)
• Key Sizes:
  • Public Key: 2249 bytes
  • Secret Key: 2289 bytes
  • Ciphertext: 4481 bytes
• NIST Round: Round 4 candidate

Security Warnings ⚠️

1. Code-Based: Different assumption than lattice schemes
2. Large Keys: Larger than lattice-based alternatives
3. Decoding Failures: Small probability of decoding failure
4. Side Channels: Requires constant-time decoding

API Functions

Standard KEM interface with code-based construction.

Security Analysis

Threat Model: HQC-128 Threat Model

The comprehensive threat analysis covers:

• Algorithm-specific attack vectors
• Implementation vulnerabilities
• Side-channel considerations
• Quantum resistance analysis (where applicable)
• Deployment recommendations

For complete security analysis and risk assessment, see the dedicated threat model documentation.

References

1. HQC Specification
2. NIST PQC Round 4

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