1- You need to apply RSA algorithm for given prime numbers p=17 and q=19. Calculate private and public key. Encrypt and decrypt message m=219 to prove that the private and public numbers you calculated are accurate.

2- You need to apply RSA algorithm for given prime numbers p=17 and q=11. Calculate private and public key. Encrypt and decrypt message m=88 to prove that the private and public numbers you calculated are accurate.

3- Alice and Bob want to communicate over an insecure medium. Design, on the basis of a shared secret key K_AB, a protocol, which enables Alice and Bob to authenticate each other. Assume that the shared secret key K_AB is known in advance to both partners. b.) What are the disadvantages related to the use of a shared secret key?

4- Alice and Bob want to communicate over an insecure medium. Design, on the basis of a shared secret key KAB, a protocol, which enables Alice and Bob to authenticate each other. Assume that the shared secret key KAB is not known in advance to both partners.