Exercise $1$:

Given the following Playfair matrix, answer the questions given below:

a$)$ Encrypt the plaintext: football is fun. Divide plaintext into groups of two letters,

and assume the padding character is the letter $\text{'}x\text{'}.$

Plaintext in $2-$Letter groups

Show the ciphertext for each $2-$letter group of the plaintext:

Ciphertext in $2-$Letter groups

Final Ciphertext:

b$)$ Decrypt the ciphertext: KGHNMCIUKLPDICAPQIMKKLBFAU

Plaintext: