Microsoft® Windows® 2000 Security Handbook

Concepts of Kerberos

With that little background of Kerberos security, look at the two main concepts of Kerberos, shared secrets and multiple authentication.

Shared Secrets

The Kerberos protocol relies on an authentication technique called shared secrets. What this means is that I know a secret and I tell only you what the secret is. The secret is then only known between you and me, unlike the secrets you shared with your school buddies. An analogy of this would be if I were to tell you a secret and so that you could be sure it is me when you receive communications referencing the secret, I include a password. By telling you what the password is beforehand, we have a shared secret. However, this method can be compromised. What if someone overheard ...