Yesterday, Chandler asked about an overview of the new PQC algorithms, including hybrids, for non-cryptographers. And since I’m currently procrastinating writing something about TLS, I might as well write that overview first.
Unfortunately, I am a cryptographer, which means I easily forget that the average person probably only knows what AEADs, Key Agreements, and of course Digital Signatures do.
NIST has standardized three new algorithms, going by the names ML-KEM (aka FIPS 203 aka Kyber), ML-DSA (aka FIPS 204 aka Dilithium) and SLH-DSA (aka FIPS 205 aka SPHINCS+). The first is a Key Encapsulation Method, the other two are digital signature schemes. One thing they all have in common is their comparatively much larger sizes for public keys, ciphertexts, and signatures.
Additionally, I will also discuss X-Wing, a hybrid Key Encapsulation Method combining both classical and PQ algorithms, which is currently making its way through IETF.