Defending against future threats: Cloudflare goes post-quantum

This post details Cloudflare's deployment of hybrid post-quantum key agreement in TLS 1.3, combining existing key agreements (like X25519) with new post-quantum algorithms (like Kyber). It explains the building blocks of TLS (AEAD, key agreement, signatures), the TLS 1.3 handshake flow, and the rationale behind deploying hybrid solutions for immediate protection against future quantum threats. It also discusses the challenges of migrating to post-quantum cryptography and encourages community testing.