This problem explores the use of a one$-$time pad version of the Vgenere cipher.

In this scheme, the key is a stream of random numbers between $0$ and $26.$ For example, if the key is $3195..,$ then the first letter of plaintext is encrypted with a shift of $3$ letters, the second with a shift of $19$ letters, and so on$.$

$($a$)$ Encrypt the plaintext "cryptography with the key stream $31952081210236$

$9139.15$ points$)$

$($b$)$ Using the ciphertext produced in part a$,$ find a key so that the cipherent dervys to plaintext "kennesawowls. $(15$ points$)$