2 8 15 (a) Encrypt the message "SAFE MESSAGES" using the Hill cipher with key 7 4 17 8 13. 6 Show your calculations and results. (b) (i) Construct a Playfair matrix with the key "GOOD LUCK". Make a reasonable assumption about how to treat redundant letters in the key. (ii) Use the Playfair matrix in (i) to encrypt the message: "START ATTACK NOW". (c) Encrypt the following plaintext using columnar transposition with key "MANAMA". Plaintext: APPLIED SCIENCE UNIVERSITY IS THE BEST. (d) Consider a modified Vigenere cipher where the set of characters are hexadecimal digits (instead of letters from the English alphabet). (i) If Pi is the ith digit of the plaintext, C; is the ith digit of the ciphertext, and Ki is the ith digit of the key, write equations for the encryption and decryption operations. (ii) For P=3AE60A3 and keyword = 17E, what is C? Activate Wing Go to Settings to