1. Using Vigenere cipher, encrypt the word "explanation" using the repeated key procedure and (b) autokey system 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 0 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 0 1 7 23 15 21 14 11 11 2 8 9 Using the ciphertext produced in part (a),find a key so that the cipher text dectypts to the plaintext cashnotneeded. h. 3, Consider the following letter encodings