22) b, c?

CHAPTER 3 TRADITIONAL SYMMETRIC-KEY CIPHERS 21. Encryps the message "this is an exercise"using one of the following ciphers. Ignore the space between words. Decrypt the message to get the original plaintext. a. Additive cipher with key - 20 b Multiplicative cipher with key - IS c. Affine cipher with key (15. 20 22. Encrypt the messge "the house is being sold tonighr" using one of the following a. Vigenere cipher with key olla b. Autokey cipher with key c Payfair cipher with the key created in the text(see Figure 3.13) full of surprises" 23. Usetlie 24. Use the Playfair cipher to encipher the message "The key is hidden under the door Vigenere cipher with keywordHEALTH" to encipher the message "tife is pad" The secret key can be made by biling the first and part of the second row with the word "GUIDANCE" and illing the rest of the matrix with the rest of the 8 9 CHAPTER 3 TRADITIONAL SYMMETRIC-KEY CIPHERS 21. Encryps the message "this is an exercise"using one of the following ciphers. Ignore the space between words. Decrypt the message to get the original plaintext. a. Additive cipher with key - 20 b Multiplicative cipher with key - IS c. Affine cipher with key (15. 20 22. Encrypt the messge "the house is being sold tonighr" using one of the following a. Vigenere cipher with key olla b. Autokey cipher with key c Payfair cipher with the key created in the text(see Figure 3.13) full of surprises" 23. Usetlie 24. Use the Playfair cipher to encipher the message "The key is hidden under the door Vigenere cipher with keywordHEALTH" to encipher the message "tife is pad" The secret key can be made by biling the first and part of the second row with the word "GUIDANCE" and illing the rest of the matrix with the rest of the 8 9