Assignment

Questions:

    1. What are three features that make one-time pad perfectly secure?  [3M]
    2. What is one-time pad explain with the example?  [2M]
    3.Show how to use the Vigenere cipher to encrypt any word of length t so that perfect secrecy is obtained (Note: you can choose the      length of the key)?  [3M]
    4.Prove that if only a single character is encrypted, then the shift cipher is perfectly secret?  [3M]
    5.Describe any two applications of OTP in cryptography?  [2M]
    6.What is the largest plaintext space M you can find for which the mono-alphabetic substitution cipher provides perfect secrecy(Note:      M need not contain only valid English words.)?  [4M]