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ML-KEM

Algorithm​

ML-KEM (FIPS 203) is a post-quantum key encapsulation mechanism (KEM): encapsulation yields a ciphertext plus shared secret, decapsulation recovers the same shared secret.

Purpose​

Post-quantum key encapsulation (FIPS 203).

Rust API​

  • Crate: noxtls-crypto
  • Module path (conceptual): noxtls_crypto::pkc
  • Primary symbols:
    • MlKemPrivateKey
    • MlKemPublicKey
    • noxtls_mlkem_generate_keypair_auto
    • noxtls_mlkem_encapsulate_auto
    • noxtls_mlkem_decapsulate

Functions and types:

  • noxtls_mlkem_generate_keypair_auto(drbg) - Parameters: drbg. Behavior: Generate (private, public) key pair. Returns: unspecified output.
  • noxtls_mlkem_encapsulate_auto(public, drbg) - Parameters: public, drbg. Behavior: Produce (ciphertext, shared_secret). Returns: unspecified output.
  • noxtls_mlkem_decapsulate(private, ciphertext) - Parameters: private, ciphertext. Behavior: Recover shared secret from ciphertext. Returns: unspecified output.

Feature flags and policy​

Enable PQC-related features on noxtls / noxtls-core per product matrix.

Examples​

use noxtls_crypto::{
    HmacDrbgSha256, noxtls_mlkem_decapsulate, noxtls_mlkem_encapsulate_auto, noxtls_mlkem_generate_keypair_auto,
};

let mut drbg = HmacDrbgSha256::new(b"0123456789abcdef", b"nonce", b"mlkem")?;
let (sk, pk) = noxtls_mlkem_generate_keypair_auto(&mut drbg)?;
let (ct, ss_sender) = noxtls_mlkem_encapsulate_auto(&pk, &mut drbg)?;
let ss_receiver = noxtls_mlkem_decapsulate(&sk, &ct)?;
assert_eq!(ss_sender, ss_receiver);
# Ok::<(), noxtls_core::Error>(())

Security and compatibility​

Isolate PQ keys and ciphertext sizes in firmware buffer planning.