1. Suppose in a faculty meeting, the department chair, Portia asked all of the faculty to propose a new course and send the proposals to her. Professor Edgar, doesn't care if anyone sees his proposal, but wants to make sure that Professor Angelo doesn't claim that the proposal is his or modifies it. How can Professor Edgar ensure this by using public-key cryptography? [8 points] 2. Consider a network with 50 individual users, in which all users communicate with all others at some point in time. How many unique keys are needed if using public key encryption vs symmetric key encryption? [12 points] 3. In the StackGuard approach to solving the buffer overflow problem, the compiler inserts a canary value on the memory location before the return address in the stack. The canary value is randomly generated. When there is a return from the function call, the compiler checks if the canary value has been overwritten or not. Do you think this approach would work? Why or why not? [8 points]