Status Report on the Fourth Round of the NIST Post-Quantum Cryptography Standardization Process

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.