NIST is selecting public-key cryptographic algorithms through a public, competition-like process to specify additional digital signature, public-key encryption, and key-establishment algorithms to supplement FIPS 186-5, SP 800-56Ar3, and SP 800-56Br2. These algorithms are intended to protect sensitive information well into the foreseeable future, including after the advent of quantum computers. In the fourth round of the Post-Quantum Cryptography Standardization Process, NIST selected four candidate algorithms for key establishment to be studied: BIKE, Classic McEliece, HQC, and SIKE. This report describes the evaluation and selection process of these fourth-round candidates based on public feedback and internal review. The report summarizes each of the candidate algorithms and identifies those selected for standardization. The only key-establishment algorithm that will be standardized is HQC, and NIST will develop a standard based on HQC to augment its key-establishment portfolio.
HQC gets standardized, as an addition to ML-KEM (kyber). McEliece is out of the NIST process for two reasons, they consider it unlikely to be widely used, also ISO is considering standardizing it and they don’t want to create an incompatible standard. If ISO does standardize it and it does see use, NIST is considering mirroring that standard (since lots of US agencies are bound to using NIST standards)
