QUESTION 1:

(a) What are the indispensable ingredients of a symmetric cipher?

(b) What are the two basic meanings used in symmetric encryption algorithms?

(c)How many keys are needed for two people to communicate via a cipher?

(d) What is the disparity between a block cipher and a stream cipher?

(e) What are the two approaches to attacking a cipher?

(f) What is the disparity between an unconditionally secure cipher and a computationally secure cipher?

(g) Briefly express the Caesar cipher?

QUESTION 2:

(a) What is the dissimilarity between diffusion and confusion?

(b) Which parameters and design choices determine the actual algorithm of a feistel cipher?

(c) Put in plain words the avalanche effect.

(d) File the types of cryptanalytic attacks.

(e) What is the disparity between a mono alphabetic cipher and a poly alphabetic cipher?

QUESTION 3

(a) Briefly illustrate

i. Mix Columns.

ii. Add Round key.

(b) Confer the Key Expansion Algorithm.

(c) Elucidate in detail how you can do triple encryption with only 2 keys.

QUESTION 4

(a) Why is it not enviable to reuse a stream cipher key?

(b) Evaluate and contrast link and end-to-end encryption?

(c) What is traffic padding and what is its motive?

(d) What are the overhauls provided by PGP services?