Encrypt the plaintext sendmoremoney with the key stream

Encrypt the plaintext sendmoremoney with the key stream

 

Encrypt the plaintext sendmoremoney with the key stream

Computer Network Security

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 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

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