The TLS Post-Quantum Experiment

This post details a large-scale experiment with Google to evaluate the performance and feasibility of deploying two post-quantum key agreement algorithms (SIKE and HRSS) in TLS. The experiment measured server-side handshake durations and found that while HRSS (ostrich) generally outperformed SIKE (turkey), SIKE showed better performance for the slowest connections on some devices (Android, Linux, Windows). The experiment also analyzed factors like session resumption, IP version, and network location, finding that while they impacted overall latency, they did not significantly alter the performance gap between the post-quantum ciphers.