Submission + - Perfect Forward Secrecy Made Your Private Keys Boring (certkit.io)
todd3091 writes: The Snowden documents confirmed the NSA was running "harvest now, decrypt later" operations, recording encrypted traffic with the expectation of eventually stealing private keys. With RSA key exchange, one compromised key could decrypt years of recorded sessions. Perfect Forward Secrecy killed that attack vector. Each TLS connection generates ephemeral keys through Diffie-Hellman that get discarded after the handshake. The server's private key only authenticates identity, it never touches session encryption. TLS 1.3 made PFS mandatory in 2018, but plenty of systems still run TLS 1.2 with misconfigured ciphers. When Heartbleed hit, sites with PFS disclosed potential compromise of weeks of traffic. Sites without PFS had to disclose years.
