TLS 1.3 includes welcome improvements, but still allows long-lived secrets

The document explores how TLS 1.3’s 0‑RTT data can lack forward secrecy due to its derivation from potentially long‑lived secrets, enabling future decryption and posing replay risks, and uses this to illustrate broader systems tradeoffs between performance and security. Drawing on authoritative RFC discussions rather than LLM outputs, it emphasizes that application and protocol design choices (e.g., enabling 0‑RTT, handling replay, use of QUIC, and UI signals) must balance threat models with latency and functionality in a holistic systems approach.