Operation Manual

136
Technical Details
Notation
C Ciphertext block
D
K
() Decryption algorithm using encryption/decryption key K
E
K
() Encryption algorithm using encryption/decryption key K
H() Hash function
i Block index for n-bit blocks; n is context-dependent
K Cryptographic key
P Plaintext block
^ Bitwise exclusive-OR operation (XOR)
 Modulo 2
n
addition, where n is the bit size of the left-most operand and of the
resultant value (e.g., if the left operand is a 1-bit value, and the right operand is a
2-bit value, then: 1  0 = 1; 1  1 = 0; 1  2 = 1; 1  3 = 0; 0  0 =
0; 0  1 = 1;
0  2 = 0; 0  3 = 1)
 Modular multiplication of two polynomials over the binary field GF(2) modulo
x
128
+x
7
+x
2
+x+1 (GF stands for Galois Field)
|| Concatenation