Towards Post-Quantum Cryptography in TLS

This post details Cloudflare's involvement in the transition to post-quantum cryptography (PQC) for TLS. It explains the threat posed by quantum computers to current public-key cryptography, the ongoing NIST standardization process, and the characteristics required for PQC algorithms in TLS (latency, key size, design clarity, hardware use). Cloudflare is experimenting with two candidate algorithms, HRSS-SXY (lattice-based) and SIKE (isogeny-based), in a joint experiment with Google. The experiment aims to collect telemetry on TLS handshakes using these algorithms to understand their real-world performance, latency impacts, and interactions with network middleboxes. The post also discusses the trade-offs between speed and size for these algorithms compared to X25519.