C |
Ciphertext block |

DK() |
Decryption algorithm using encryption/decryption key K |

EK() |
Encryption algorithm using encryption/decryption key K |

H() |
Hash function |

i |
Block index for n-bit blocks; n is context-dependent |

K |
Cryptographic key |

^ |
Bitwise exclusive-OR operation (XOR) |

⊕ |
Modulo 2n 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 x128+x7+x2+x+1 (GF stands for Galois Field) |

|| |
Concatenation |