Prepping for post-quantum: a beginner’s guide to lattice cryptography

This tutorial introduces lattice-based post-quantum cryptography for the TLS transition, building from a noisy matrix-based encryption scheme to ML-KEM (Kyber) for key encapsulation and ML-DSA (Dilithium) for signatures. It explains the LWE/SIS hardness foundations, how noise and short vectors enable security while managing decryption errors, achieving CCA security, and improving efficiency via polynomial rings and NTT, with practical sizes (e.g., ML-KEM-768 pk 1184 B, ct 1088 B; ML-DSA-44 pk 1312 B, sig 2420 B). The post highlights current deployment progress (e.g., Cloudflare’s PQ encryption adoption), engineering trade-offs like compression and parameter tuning, and notes broader lattice applications such as FHE.