This problem explores the use of a one-time pad version of the Vigenre cipher. In this scheme,

This problem explores the use of a one-time pad version of the Vigenère cipher. In this scheme, the key is a stream of random numbers between 0 and 26. For example, if the key is \(3195 \ldots\), 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

\[
\begin{array}{lllllllllllll}
9 & 0 & 1 & 7 & 23 & 15 & 21 & 14 & 11 & 11 & 2 & 8 & 9
\end{array}
\]

b. Using the ciphertext produced in part (a), find a key so that the cipher text decrypts to the plaintext cashnotneeded.