What is Perfect Forward Secrecy (PFS)

Perfect Forward Secrecy (PFS) is a configurable property for IKEv1 Phase 2 (Quick Mode). Perfect Forward Secrecy (PFS) is a method for deriving fresh Phase 2 keys independent from previous keys. Perfect Forward Secrecy (PFS) forces the peers to generate new shared secret during the Phase 2 (Quick Mode) message exchange.

Perfect Forward Secrecy (PFS) can improve the network security to much higher level, because if a hacker hacked and compromised a key, he would only be able to access data protected only by the hacked key. Other future communication is still secure, because future data will be encrypted using another key. Both IPSec peers must agree for Perfect Forward Secrecy (PFS) to work.