Chapter 3, Problem 3.3AYK

Using R language

Compare the security services provided by a digital signature (DS) with those of a message authentication code (MAC). Assume that Oscar can observe all messages sent between Rina and Naseem. Oscar has no knowledge of any keys but the public one, in the case of DS. State whether DS and MAC protect against each attack and, if they do, how. The value auth(x) is computed with a DS or a MAC algorithm. In each scenario, assume the message M = x#####auth(x). (Message integrity) Rina has the textual data x = “Transfer $1000 to Mark” to send to Naseem. To ensure the integrity of the data, Rina generates auth(x), forms a message M, and then sends M in cleartext to Naseem. Oscar intercepts the message and replaces “Mark” with “Oscar.” Will Naseem detect this in the case of either DS or MAC? If yes, how will Naseem detect it? If not, why? (Replay) Rina has the textual data x = “Transfer $1000 to Mark” to send to Naseem. To ensure the integrity of the data, Rina generates auth(x), forms a message…

I need to resolve the following....You are trying to convince your boss that your company needs to invest in a license for MS-Project (project management software from Microsoft) before beginning a systems project. What arguments would you give her?