PAP Password Authentication Protocol, PAP, a method of authentication used to verify the identity of a user who tries to log on to a PPP server (e.g. through dial-up). The user’s name and (optionally encrypted) password are transmitted over the network and compared to a secret table of name/password pairs on the server. The main weakness of PAP is that the technique can be vulnerable to eavesdroppers who may try to obtain the password by listening in on the serial line. The Basic Authentication feature built into the HTTP protocol uses PAP.
