What Does Perfect Forward Secrecy Mean?
Perfect Forward Secrecy (PFS) is a data encoding property that ensures the integrity of a session key in the event that a long-term key is compromised. PFS accomplishes this by enforcing the derivation of a new key for each and every session.
Techopedia Explains Perfect Forward Secrecy
PFS works on a very simple concept to ensure the safety of session keys from future exploitation by hackers. Encoded messages are encrypted using sophisticated mathematical formulas, where decryption would require massive processing, making building practically impossible with the current computing architecture. However, a hacker theoretically could save an encrypted message with the intention of decrypting it in the future, perhaps when greater computing power is available. PFS is designed to eliminate this threat by periodically creating new keys. So, even if a hacker exploits a private key in the future, he is unable to decrypt previously transmitted messages.