ML-KEM

This crate implements all three ML-KEM (FIPS 203 (Initial Public Draft)) variants 512, 768, and 1024. It is formally verified using hax and F*.

Functions in this crate use CPU feature detection to pick the most efficient version on each platform. To use a specific version with your own feature detection use e.g. one of the following

• mlkem768::avx2::generate_key_pair,
• mlkem768::neon::generate_key_pair,
• mlkem768::portable::generate_key_pair,

analogously for encapsulation and decapsulation.

 use rand::{rngs::OsRng, RngCore};

 // Ensure you use good randomness.
 // It is not recommended to use OsRng directly!
 // Instead it is highly encouraged to use RNGs like NISTs DRBG to account for
 // bad system entropy.
 fn random_array<const L: usize>() -> [u8; L] {
     let mut rng = OsRng;
     let mut seed = [0; L];
     rng.try_fill_bytes(&mut seed).unwrap();
     seed
 }

 use libcrux_ml_kem::*;

 // This example uses ML-KEM 768. The other variants can be used the same way.

 // Generate a key pair.
 let randomness = random_array();
 let key_pair = mlkem768::generate_key_pair(randomness);

 // Encapsulating a shared secret to a public key.
 let randomness = random_array();
 let (ciphertext, shared_secret) = mlkem768::encapsulate(key_pair.public_key(), randomness);

 // Decapsulating a shared secret with a private key.
 let shared_secret_decapsulated = mlkem768::decapsulate(key_pair.private_key(), &ciphertext);

Features

By default, all ML-KEM parameter sets are enabled. If required, they are available individually under feature flags mlkem512, mlkem768, mlkem1024.

In addition to the verified implementations of the ML-KEM variants, the feature flag pre-verification gives access to, as yet, unverified implementations of ML-KEM that are optimized for SIMD instruction sets.

Kyber Round 3

The kyber flag (in combination with pre-verification) also gives access to an, as yet, unverified implementation of Kyber as submitted in Round 3 of the NIST PQ competition.