PPP Authentication Protocols: Password Authentication Protocol (PAP) and Challenge Handshake Authentication Protocol (CHAP)
(Page 2 of 3)
Password Authentication Protocol (PAP).
PAP is a very straight-forward authentication scheme, consisting of only two basic steps, as shown in Figure 29:
Simple. Now, remember what Einstein said about simplicity? PAP is another example of something that is just too simple for its own good. Chief amongst its flaws is that it transmits the user name and password in clear text across the link. This is a big no-no in security protocols, as it means any eavesdropper can get the password and use it in the future. PAP also provides no protection against various security attacks. For example, an unauthorized user could simply try different passwords indefinitely and hope he or she eventually found one that worked. PAP also puts control of the authentication squarely on the shoulders of the initiating device (usually a client machine) which is not considered desirable.
Home - Table Of Contents - Contact Us
The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005
© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.