Kyber (CRYSTALS-Kyber)

Kyber, formally CRYSTALS-Kyber, is the original name of the lattice-based key encapsulation mechanism that NIST standardized as ML-KEM in FIPS 203. It was submitted to the NIST Post-Quantum Cryptography Standardization process in 2017 and selected for standardization in 2022.

#From Kyber to ML-KEM

When NIST prepared the final standard it renamed the algorithm ML-KEM (Module-Lattice-Based Key-Encapsulation Mechanism) and published it as FIPS 203 in August 2024. The standardized version differs in some details from the original Kyber submission, so an implementation of one is not automatically interoperable with the other. In current usage the two names refer to essentially the same design: a Key encapsulation mechanism whose security rests on lattice problems. Documentation and libraries written before 2024 typically use the Kyber name, while standards-compliant deployments use ML-KEM.