Automatic Key Exchange: faster, post-quantum secure origin handshakes for 45 billion daily connections (and counting)

Cloudflare rolled out Automatic Key Exchange, measuring origin support and leading with the optimal algorithm, cutting HelloRetryRequests from 52% to 3.7% and shaving over 150 ms at p90. The change also automatically enables post‑quantum hybrid X25519‑MLKEM768 where possible, without operator configuration.