Tag:Inverse element

  • Affine cipher


    Affine cipher The idea of affine cryptography is to multiply the plaintext by a part of the key, and then add the rest of the key. Suppose x, y, a, B, Z_ {26}\\ Decryption can be easily derived from encryption functions a·x+b\equiv y\ mod\ 26\\ a·x\equiv (y-b)\ mod \ 26\\ x\equiv a^{-1}·(y-b)\ mod\ 26 The […]

  • Integer ring


    ring Integer ringZ_mIt consists of the following two parts: 1. AssemblyZ_m = ( 0,1,2,…,m )2. Two kinds of operations “+” and “X” make thea, b\in Z_myes: a + b\equiv c\ mod\ m, (c\in Z_m)\\ a\times b\equiv d\ mod\ m, (d\in Z_m) Key features of rings If the result of the addition or multiplication of any […]