1. Suppose you are the security manager of a company and one of your goals is to design security mechanisms based on three security goals (1) prevent the attack (2) detect the attack or (3) recover from the attack. Depending on the situation or application, you have to adopt one of these security goals. For each of the following statements, give an example of an application or situation in which the statement is true. [10 points]

   (i). Prevention is more important than detection and recovery (ii). Detection is more important than prevention and recovery (iii). Recovery is more important than prevention and detection

2. Policy restricts the use of electronic mail on a particular system to faculty and staff. Students cannot send or receive electronic mail on that host. Classify the following mechanisms as secure, precise, or broad. Provide adequate rationale for your all your answers. [10 points]

   a. The electronic mail sending and receiving programs are disabled.

b. As each letter is sent or received, the system looks up the sender (or recipient) in a database. If that party is listed as faculty or staff, the mail is processed. Otherwise, it is rejected. (Assume that the database entries are correct.)

c. The electronic mail sending programs ask the user if he or she is a student. If so, the mail us refused. The electronic mail receiving programs are disabled.