NIST has selected a new algorithm called HQC as a backup for ML-KEM, designed to protect data from future quantum computer attacks. This HQC algorithm uses different math concepts, effectively providing a second layer of defense for general encryption. While ML-KEM remains the primary choice for encryption, HQC serves as a precautionary measure. Although HQC demands more resources due to its lengthier nature, NIST deems it a necessary backup in the face of potential cryptographic vulnerabilities. HQC is part of NIST’s larger efforts in post-quantum cryptography to ensure data security in the future.
https://www.nist.gov/news-events/news/2025/03/nist-selects-hqc-fifth-algorithm-post-quantum-encryption