Data Encryption Standard   Perform a Data Encryption Standard encryption on the plaintext (PL) by using key (K). The PL is your first 8 characters of your name and K is the last 8 digits of your student ID.

Public key cryptosystems are: (more than one may be true, choose all that are true) a offering a simpler way for key distribution B faster than symmetric C the preferred solution when the message we want to encrypt is very large D easily used to offer integrity E requiring advanced hardware in order to use them F easily used to offer confidentiality G marketed better than symmetric that is why people prefer them H using one key for encryption and a different key for decryption

Cryptography: Alice’s modulus is 11292367, her public exponent is e=94321 and her private exponent is d=6327241.  Use RSA to sign the message:  x=08041115

 Block size = 8 bits Hash size = 8 bits Encryption function: Divide the key into two halves: LK and RK; Divide the plaintext into twohalves: LT and RT; Then ciphertext= LC||RC where LC=LK XOR RT; and RC = RK XOR LT;where LC, RC, LT, and RT are each 4 bits; Plaintext and ciphertext are each 8 bits. g(H) = an 8-bit string that is equal to the complement of bits in H; For example, if H=A3 (Hexa)= 10100011 (binary); then g(H)= 01011100 H0 = Initial hash = 11001010   Given a message m: CAB2 (in Hexa);Q1. Determine the hash (in hexadecimal) of the message M using Martyas-Meyer-Oseas hashfunction (Fig. 11.7). Q.2 Determine the hash (in hexadecimal) of the message M using Davis-Meyer hash function(Fig. 11.6) Q.3 Determine the hash (in hexadecimal) of the message M using Migayuchi-Preneel hashfunction (Fig. 11.6)