Question 4: Computex as far as possible without a calculator. Where appropriate, make use of a smart decomposition of the exponent as shown in the example in Sect. 1.4.1: a. x 32 mod 13 b. x 72 mod 13 c. x 310 mod 13 d. x 100 mod 13 e. 7 11 mod 13 Question 5 Suppose we want to encrypt using affine cipher with a -5 and b 8. a. What is the encryption function? b. What is the decryption function? c. Decrypt the ciphertext: HPCCXAQ using this affine cipher Question 6: Suppose we want to encrypt using affine cipher with a .5 and b 8. a. What is the encryption function? b. What is the decryption function? c. Encrypt the plaintext: ITS COOL using this affine cipher