CRYSTALS-KYBER

NIST lattice-based ML-KEM Kyber KEM.

Definition

Kyber parameter sets: Kyber512 (Security Level 1 ~AES-128), Kyber768 (Level 3 ~AES-192, recommended most uses), Kyber1024 (Level 5 ~AES-256). Sizes: Kyber768 public key 1184 bytes, ciphertext 1088 bytes, shared secret 32 bytes. Performance: ~10000x faster than RSA-3072 KeyGen, ~100x faster KEM. Open-source implementations: pqcrystals/kyber (reference C), liboqs (Open Quantum Safe project), Cloudflare CIRCL Go, BoringSSL, OpenSSL 3.5 (planned).

Origin

CRYSTALS-Kyber submitted to NIST PQC Round 1 November 2017 ; survived Round 2, 3 ; selected NIST PQC standard July 2022 ; standardised FIPS 203 13 August 2024.

Example in context

Signal Protocol (Whisper Systems) integrates hybrid Kyber768 with X25519 in its PQXDH extension (Post-Quantum Extended Diffie-Hellman) deployed since February 2024 for 1 billion Signal+WhatsApp users.

Related terms

• CRYSTALS Dilithium — partner signature.