Part 1:(Encryption and Decryption) The function E(x) = (ax + b) MOD 26 defines a valid Affine cipher of a letter 'x'. the coefficients 'a' and 'b' are integers between 0 and 25, and 'a' has to be relatively prime to 26. Recall that the numerical equivalents of the English letters are as follows: 02 O A B 0 1 N 13 P 1 5 a 16 2 14 D E F 3 4 5 T U 19 20 G H I 6 7 8 V W 21 2 2 J K L M 9 10 11 1 2 X Y z 2 3 24 25 R 17 S 18 a) Encrypt the plaintext "NETWORK SECURITY" with the Affine cipher E(x) = (5x+8) mod 26. (1 pt) b) Find E."(y) the inverse function of E(x), or the decryption function. (1 pt) c) Decrypt the following ciphertext using E--(y): "WVHAPQIZWAV UCSEPWZY". (1 pt)