perfect forward secrecy

Perfect forward secrecy (PFS) is a property of cryptographic systems that ensures session keys are not compromised even if the server's long-term private key is exposed. In the context of the Heartbleed vulnerability (CVE-2014-0160), which allowed attackers to extract private memory from vulnerable OpenSSL versions, perfect forward secrecy is critical because it limits the damage: even if an attacker obtains the server's private key via Heartbleed, past session keys remain secure if PFS was used. Discussions on WindowsForum highlight that enabling PFS ciphersuites (e.g., ECDHE) is a recommended mitigation to protect encrypted communications against such key compromises. The tag covers how PFS strengthens TLS security and its relevance to vulnerabilities like Heartbleed.