"Migrating global public key infrastructure from RSA and Elliptic Curves to lattice-based cryptography to defend against Harvest Now, Decrypt Later quantum attacks."
Introduction
When scalable quantum computers emerge, Shor’s algorithm will break RSA and Elliptic Curve Diffie-Hellman (ECDH) encryption in seconds. Nation-state adversaries are actively harvesting encrypted internet traffic today to decrypt it in the future.
The Mathematics of Module-Lattice Cryptography (ML-KEM / Kyber)
Standardized by NIST, ML-KEM (formerly CRYSTALS-Kyber) relies on the hardness of the Learning With Errors (LWE) problem over algebraic module lattices. Even quantum algorithms with millions of qubits cannot solve high-dimensional lattice vector problems in polynomial time.
use pqcrypto_kyber::kyber768::*;
pub fn generate_hybrid_handshake() -> (PublicKey, SecretKey) {
let (pqc_pk, pqc_sk) = keypair();
(pqc_pk, pqc_sk)
}
Hybrid Handshakes and Packet Fragmentation Overhead
Because post-quantum public keys and ciphertexts are larger than classical keys (roughly 1,184 bytes for ML-KEM-768), network engineers use hybrid X25519 + Kyber handshakes to ensure seamless security without exceeding TCP initial congestion window (initcwnd) limits.
Key Takeaways
• Lattice-based cryptography protects data against future quantum computer decryption.
• Hybrid TLS handshakes combine classical ECDH with ML-KEM for defense-in-depth.
• Defends against "Harvest Now, Decrypt Later" espionage operations on financial and government data.
