Block size = 4 bits Hash size = 4 bits Encryption function: Divide the key into two halves: LK and RK; Divide the plaintext into two halves: LT and RT; Then ciphertext= LC||RC where LC=LK XOR RT; and...

• Block size = 4 bits


• Hash size = 4 bits


• Encryption function: Divide the key into two halves: LK and RK; Divide the plaintext into two halves: 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 2 bits; Plaintext and ciphertext are each 4 bits.


• g(H) = a 4-bit string that is equal to the complement of bits in H; For example, if H=A (Hexa) = 1010 (binary); then g(H)= 0101


• H0 = Initial hash = A (in Hexa)


• Given message M:  F1 (in Hexa);

Extracted text: Hj-1 eigggen Hj-1 m Hi Hị Fig. 11.7 Davies-Meyer (left) and Miyaguchi-Preneel hash function constructions from block ciphers


Extracted text: X1 -.. Xn b. H-1 Hị Fig. 11.6 The Matyas-Meyer-Oseas hash function construction from block ciphers