Universal SSL: How It Scales

What this post added

This post details the technical advancements enabling Cloudflare's Universal SSL, which scaled HTTPS adoption to millions of sites. It highlights the use of modern hardware with cryptographic instructions (AES-NI, CLMUL), modern cryptographic algorithms (ECDSA, ECDHE) for faster handshakes, session resumption techniques (session tickets and IDs) for returning visitors, and lazy loading of certificates to manage dynamic configurations at scale. These optimizations reduced the CPU cost of SSL to near zero, making widespread HTTPS deployment feasible.