Which authentication method transmits the username and password in plain text?

PAP, or Password Authentication Protocol, transmits the username and password in plain text during the authentication process. This means that any data sent over the network can be intercepted easily by an attacker, posing significant security risks. Since PAP does not employ any encryption or protection for these credentials, it is not suitable for environments where security is a primary concern.

In contrast, methods like CHAP (Challenge Handshake Authentication Protocol), NTLM (NT LAN Manager), and Kerberos utilize different techniques that provide a higher level of security. CHAP uses a challenge-response mechanism, so the password is not sent directly over the network. NTLM includes multiple stages of communication that authenticate users securely without transmitting passwords in plaintext. Kerberos employs strong cryptography to handle authentication, making it a much stronger choice for secure environments.

By understanding these differences, it becomes clear why PAP is recognized as weak due to its transmission of credentials in plaintext, while other methods offer enhanced security protocols.