Data Communications and Computer Networks by Pearson

290 Data Communications and Computer Networks

with the received MAC to determine whether they are same or not. If so, the receiver knows that the

message has not been changed and is actually from the intended sender and thus, accepts the message.

Otherwise, the message is discarded.

 19. Encrypttheplaintext6usingRSApublickeyencryptionalgorithm.Useprimenumbers

11 and3 to computethepublic andprivate keys.Moreover,decryptthe ciphertextusingthe

privatekey.

 Ans: Here, m = 11 and n = 3

According to RSA algorithm (as explained in Q12)

p = m * n = 11 * 3 = 33

q = (m − 1) * (n − 1) = (11 − 1) * (3 − 1) = 10 * 2 = 20

We choose ...