This problem explores the use of a one-time pad version of the Vigenere cipher. In this scheme, the key is a stream of random numbers between O and 26. For example, if the key is 3 19 5 ... , then the first letter of plaintext is encrypted with a shift of 3 lettters, the second with a shift of 19 letters, the third with a shift of 5 letters, and so on.

1. a) Encrypt the plaintext sendmoremoney with the key stream 2 9 0 1 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.