NIST Selects HQC As Fifth Algorithm For Post-Quantum Encryption, Adding Backup Security

NIST has selected HQC as a fifth algorithm for post-quantum encryption, designed to serve as a backup to ML-KEM, which is the primary algorithm for general encryption. Unlike ML-KEM, which relies on structured lattices, HQC is based on error-correcting codes, offering an alternative mathematical approach that could enhance security if vulnerabilities in ML-KEM are discovered. NIST plans to release a draft standard incorporating HQC within approximately one year and finalize the standard by 2027.

The selection of HQC follows NIST’s fourth round of candidate evaluation, during which four algorithms were considered for standardization. A report detailing the evaluation and rationale behind HQC’s selection has been published. NIST plans to release a draft standard for public comment in approximately one year, with finalization expected by 2027.

HQC joins other post-quantum encryption algorithms already standardized or under development by NIST, including those focused on digital signatures such as FALCON and SPHINCS+. These efforts aim to provide robust cryptographic tools that can withstand attacks from future quantum computers.

HQC is a key encapsulation mechanism (KEM) designed as a backup algorithm for post-quantum encryption. Unlike ML-KEM, which relies on structured lattices, HQC is based on error-correcting codes, specifically binary Goppa codes. This foundation offers an alternative pathway to achieving cryptographic security.

The selection of HQC as a backup algorithm aligns with NIST’s broader strategy to develop multiple secure cryptographic tools capable of resisting quantum attacks. By diversifying the mathematical approaches underpinning these algorithms, NIST aims to enhance the resilience of cryptographic systems against emerging threats.

HQC and ML-KEM are key encapsulation mechanisms (KEMs) designed for post-quantum cryptography, aiming to secure communications against quantum computer attacks. ML-KEM is based on structured lattices, leveraging their mathematical properties for security, while HQC utilizes binary Goppa codes from error-correcting code theory. HQC serves as a backup to ML-KEM, offering redundancy and mitigating risks if one method proves vulnerable.

NIST has selected HQC after rigorous evaluation and plans to standardize it by 2027. This dual approach with different mathematical foundations enhances cryptographic resilience against quantum threats.