Previously intercepted communications must remain secure even if a current encryption key is compromised in...

Forward secrecy (FS) ensures that past encrypted data remains secure even if encryption keys are compromised in the future. Itgenerates ephemeral session keys that are not reused.

Other options:

A (Tokenization) replaces sensitive data with tokens but does not prevent key compromise.

B (Key stretching) makes brute-force attacks harder but does not ensure secrecy after compromise.

D (Simultaneous Authentication of Equals – SAE) is used in WPA3 but is not related to past communication security.