Ciphertext: W$->22$

Ciphertext: T$->19$

Ciphertext: A $->00$

Ciphertext: A $->00$

Ciphertext: D $->03$

Decryption: $(22-15)$mod$26$

Decryption: $(19-15)$mod$26$

Decryption: $(00-15)$mod$26$

Decryption: $(00-15)$mod$26$

Decryption: $(03-15)$mod$26$

Plaintext: $07->$h

Plaintext: $04->$e

Plaintext: $11->1$

Plaintext: $11->1$

Plaintext: $14->0$

Lab Task $2($Individual Task$)$

$1-$ Use the additive cipher with key $=5$ to encrypt the message "student".

$2-$ Use the additive cipher with key $=5$ to decrypt the message "XYZIISY".

$3-$ Provide Mathematical description of the "student" and "XYZIISY".