ty of the integei V, = 313 = 12 (mod 43) PROBLEMS 10.3 forwarded to a user with public key (47, 5, 10) and private key k - %D () Indicate how the ciphertext can be decrypted using the recipient's...

Question 4

Extracted text: ty of the integei V, = 313 = 12 (mod 43) PROBLEMS 10.3 forwarded to a user with public key (47, 5, 10) and private key k - %D () Indicate how the ciphertext can be decrypted using the recipient's privnertex 2. Suppose that the following ciphertext is received by a person having EIGam key (71, 7, 32) and private key k = 30: (56, 45) (56, 38) (56, 29) (56, 03) (56, 67) (56, 05) (56, 27) (56, 31) (56, 38) (56, 29) Obtain the plaintext message. 3. The message NOT NOW (numerically 131419131422) is to be sent to a user of th EIGamal system who has public key (37, 2, 18) and private key k = 17. If the inten j used to construct the ciphertext is changed over successive four-digit blocks from j = 13 to j = 28 to j = 11, what is the encrypted message produced? 4. Assume that a person has ElGamal public key (2633, 3, 1138) and private key k = 965. If the person selects the random interger j = 583 to encrypt the message BEWARE OF THEM, obtain the resulting ciphertext. [Hint: 3583 = 1424 (mod 2633), 1138583 = 97 (mod 2633).] 5. (a) A person with public key (31,2,22) and private key k = 17 wishes to sign a message whose first plaintext block is B = 14. If 13 is the integer chosen to construct ue signature, obtain the signature produced by the ElGamal algorithm. (b) Confirm the validity of this signature. %3D %3D %3D %3D