Kerberos is a network authentication protocol created by MIT, and uses symmetric-key cryptography[18] to authenticate users to network services, which means passwords are never actually sent over the network.
Consequently, when users authenticate to network services using Kerberos, unauthorized users attempting to gather passwords by monitoring network traffic are effectively thwarted.
[18] A system where both the client and the server share a common key that is used to encrypt and decrypt network communication.