The Kerberos protocol is built to protect authentication between the server and the client in an open network. The main concept behind authentication is that two parties first agree on a password (secret) and then use it to both identify and verify their genuineness:
In the preceding example, Dave and server A have regular communications. They often exchange confidential data. In order to protect this communication, they agree to use a common secret code (1234) to verify their identities before exchanging data. When Dave makes initial communication, he passes his secret to server A and says Hey! I'm Dave. Then, server ...
