Choose one cryptographic password-based authentication protocol that you normally use.

- What is the detailed protocol specification for your chosen authentication protocol?

- Consider whether this protocol is secure against off-line dictionary attacks. If yes, provide a heuristic security proof. If not, how would someone mount an off-line dictionary attack?

- Can you revise or redesign the protocol so that it is secure against off-line dictionary attacks? Please describe your detailed protocol design and provide a heuristic security proof.