Which PPP authentication method sends authentication information in clear text?

Which PPP authentication method sends authentication information in clear text?
A . MS CHAP
B . CDPCP
C . CHAP
D . PAP

View Answer

Answer: D

Explanation:

PAP authentication involves a two-way handshake where the username and password are sent across the link in clear text; hence, PAP authentication does not provide any protection against playback and line sniffing. CHAP authentication, on the other hand, periodically verifies the identity of the remote node using a threeway handshake. After the PPP link is established, the host sends a "challenge" message to the remote node. The remote node responds with a value calc“lated usi”g a one-way hash function. The host checks the response against its own calculation of the expected hash value. If the values match, the authentication is acknowledged; otherwise, the connection is terminated.

Reference: http://www.cisco.com/c/en/us/support/docs/wan/point-to-point-protocol-ppp/10241-ppp­callinhostname. html