Which method utilizes simple passwords and the challenge handshake authentication process?

The method that utilizes simple passwords and the challenge handshake authentication process is EAP-MD5. EAP-MD5 is an Extensible Authentication Protocol that employs a straightforward method of authentication using a username and password.

In the challenge handshake authentication process, the server sends a challenge to the client, which must then respond with a hashed value created from their password and some challenge data. This allows the server to verify the identity of the client without directly transmitting the password over the network. The simplicity of EAP-MD5 makes it easy to implement; however, it does lack some security features found in more advanced EAP methods, such as mutual authentication and encryption, making it less suitable for environments where security is a significant concern.

The other methods mentioned in the options have different mechanisms and requirements. For instance, Kerberos utilizes tickets and symmetric key cryptography rather than simple passwords. EAP-TTLS and EAP-TLS both require more complex setups involving certificates for secure authentication, which significantly differ from the straightforward approach of EAP-MD5.