a) Explain the difference between a key agreement protocol and a key exchange protocol. (6 Marks) b) Compare and contrast two key agreement protocols of your own choosing at least one of which must be a quantum based protocol. Include the algorithms employed and specify those parts of the algorithms that employ classical techniques and those that employ quantum techniques. Give references for each of the algorithms discussed. (9 Marks) What is meant by the expression Quantum Parallelism? Shor's factorisation algorithm is an example of an algorithm that employs quantum parallelism and as a result is considered a major threat to the concept of public key cryptography. Explain the nature of this threat, the significance of quantum parallelism over classical parallelism. Include in your discussion, the main features of Shor's algorithm. Justify all claims. (10 Marks) c)