TLS 1.3 Improvements and Optimizations

The latest version of the protocol, TLS 1.3, introduces significant improvements in both security and performance. One of the most notable enhancements is the streamlined handshake process, which can complete in just one round trip between client and server, compared to two round trips in earlier versions. This reduction in latency provides faster connection establishment, particularly beneficial for mobile users and applications requiring quick response times.

TLS 1.3 also implements a "0-RTT" (zero round trip time) mode for resumed connections, allowing clients to send application data immediately without waiting for the handshake to complete. While this feature offers performance benefits, it requires careful implementation to prevent replay attacks. The protocol includes safeguards and recommendations for when 0-RTT mode should and shouldn't be used.

Security improvements in TLS 1.3 include the removal of outdated cryptographic algorithms and the requirement for forward secrecy in all key exchanges. The protocol mandates the use of authenticated encryption with associated data (AEAD) algorithms, combining encryption and authentication into a single operation. These changes reflect lessons learned from decades of SSL/TLS deployment and analysis of real-world attacks.