In this exercise we consider the Simple Substitution Cipher as a 5-bit block cipher. The letters A = 1, B = 2, C = 3…..Z = 26 are first represented as binary strings (5 bits per letter) as follows: A = 00001, B = 00010, C = 00011, …Z= 11010. Let the key of a Simple Substitution Cipher be given by (plaintext in top row above is replaced by bold ciphertext in bottom row):

(a)  Write the plaintext TODAY as a binary string.