OpenSSL Position and Plans on Private Key Formats for the ML-KEM and ML-DSA Post-quantum (PQ) Algorithms

The anticipated future arrival of cryptographically relevant quantum computers (CRQCs), that could undermine the algorithms that underlie the currently most widely used public key algorithms (ECDHE, ECDSA, DH and RSA), has led to the development and recent standardisation of new “post-quantum” (PQ) algorithms, that are believed to not be vulnerable to CRQC attack.
Two of the first algorithms standardized are ML-KEM (for key agreement) and ML-DSA (for digital signatures). These algorithms are standardized by NIST in FIPS 203 and FIPS 204.