Discussion Questions for Week 7: 1. "The whole idea of a security perimeter protected by a firewall is fatally flawed, because if we cannot trust machines to handle traffic from outside correctly without the need for a firewall, then we cannot trust them to handle traffic correctly from inside either." Discuss. 2. In RSA, the roles of encryption and decryption keys are interchangeable. (Why?) Does this affect how RSA is used in practical applications? 3. In Kerberos, why is the client/server session key invented by the ticket server, rather than simply by the client?