Set Up Certificates for Decrypting Internet Traffic
If you have already set up certificates for this purpose for the intrusion prevention feature, you may not need to do anything more.
Internet traffic must be decrypted in order to allow it to be inspected by the intrusion prevention and web security features, to apply acceptable use controls, for rules in which the rule action is Isolate or Warn, and to display end-user notifications when destinations are blocked.
In order to decrypt this traffic, certificates are required.