2. This problem explores the use of a one-time pad version of the Vigenre cipher. In this scheme, the key is a stream of random numbers between U and 26. For example, if the key is 3 19 5..., then the first letter of plaintext is encrypted with a shift of 3 letters, the second with a shift of 19 letters, the third with a shift of 5 letters, and so on. a. Encrypt the plaintext sendmoremoney with the key stream 9 01 7 23 15 21 14 11 11 2 8 9 b. Using the ciphertext produced in part (a). find a key so that the cipher text decrypts to the plaintext cashnotneeded 3. Consider the following letter encodings: letter |A E I MOR T |V encoding 000 001 010 011 100 101110 111 A message M = MARIO is Vernain encrypted into ciphertext C AOAI/V: C' = Me. K. where shows modulo 2 XOR operation. Find corresponding encryption key. Provide details of your cryptanalaysis 4. DES Ilustration This problem provides a numerical example of encryption using a one-round ver- sion of DES 0123456789 A BCDEF