Designing a Secure Authentication System

A nice article which tells you how to design a Secure Authentication System, through dialogs of characters Athena and Euripides.

Designing an Authentication System: a Dialogue in Four Scenes

Through the dialogues the characters design the fictitious open network authentication system called 'Charon'. The charon has striking resemblences to the Kerberos System...

Kerberos

Tail Piece:
Dan Brown has popularized the Bergofsky Principle in his book Digital Fortress. It states that any encrypted message can be decrypted if a computer tried enough keys; atlest it is mathematically guaranteed!
But the issue of time is the constraint here; with the key length increasing it may take years to decrypt the message and by that time, the message may become irrelevant.

Is there something called Bergofsky Principle, or is it just a fictitious principle? Well, googling tells that there is no such principle!