Automatic Key Exchange: faster, post-quantum secure origin handshakes for 45 billion daily connections (and counting)
Cloudflare's Automatic Key Exchange probes origins to lead with preferred key exchange, cutting HelloRetryRequests from 52% to 3.7% and enabling automatic post-quantum origin connections.
Cloudflare announced Automatic Key Exchange, an extension of Automatic SSL/TLS that probes each origin's supported key agreement algorithms and leads with the preferred one, favoring the post-quantum hybrid X25519MLKEM768. Rollover across roughly 45 billion daily origin connections cut HelloRetryRequests from about 52% to 3.7%, saving more than 150 ms of p90 handshake latency. Hundreds of thousands of domains now receive post-quantum origin connections without manual configuration, supporting Cloudflare's goal of quantum-safe encryption by 2029 to counter harvest-now-decrypt-later attacks.