a) What is meant by perfect secrecy? Give characterization of perfect secrecy. (Unit 1)

b) What do you mean by encryption? Discuss onetime pad encryption technique. (Unit 1)

a) Discuss the applications of Pseudorandom Generators (PRGs) in cryptography. (Unit 1)

b) With the help of a suitable figure discuss symmetric encryption technique. (Unit 1)

a) What do you know about the term block ciphers? Discuss modes of operations of block ciphers. (Unit 2)

b) What is the need for message authentication? List various techniques used for message authentication. Explain any one. (Unit 2)

a) Write about different types of security attacks on computer network. Give a classification of attacks. (Unit 1)

b) What are the applications of Hash function in cryptography? (Unit 3)

Discuss following terms in detail. (Unit 3)

i) Birthday attack

ii) Key exchange problem

iii) One way trapdoor

a) What do you mean by Secret Key Cryptography and Public Key Cryptography? How they are different from one another. (Unit 4)

b) With the help of a suitable example write and explain Diffie-Hellman Key Exchange algorithm. (Unit 4)

a) Explain RSA algorithm. Perform encryption and decryption using RSA algorithm for $p=3$, $q=11$ and $e=7$, $M=5.$ (Unit 5)

b) What is Digital Signature? Explain digital signature standard. (Unit 5)

Write short notes on any two of the followings:

a) Brute Force Attack (Unit 1)

b) Elliptic curve cryptography (Unit 4)

c) Cryptanalysis (Unit 1)