Post-Quantum Cryptography Migration: Kyber And Dilithium in TLS 1.3

Abstract

A sufficiently capable quantum computer would break the public-key cryptography that secures the modern internet, and data captured today can be stored until that machine arrives. This harvest-now-decrypt-later threat has pushed standards bodies to act well ahead of the hardware. In 2024 NIST published the first finished post-quantum standards: ML-KEM, derived from CRYSTALS-Kyber, for key establishment, and ML-DSA, derived from CRYSTALS-Dilithium, for digital signatures. This paper examines how these algorithms move into the two protocols that carry most secured traffic, TLS 1.3 and IPsec. We describe the hybrid handshake that runs a classical and a post-quantum key-encapsulation mechanism side by side, we measure the cost of the larger keys and signatures these schemes carry, and we discuss the practical friction points such as oversized certificate chains and fragmented handshake records. Benchmarks reported in the literature show that a hybrid X25519 plus Kyber-768 handshake adds only a small latency penalty on a healthy network, while Dilithium signatures inflate the certificate path enough to matter on constrained links. We close with a staged migration plan built around crypto-agility.