|
Invented by Lester Hill in 1929, Hill's polygraphic substitution cipher is based on linear algebra, modulo arithmetic, and some number theory. Hill used matrices to mix up the plaintext. Both encrypting and decrypting hill ciphers needs a basic understanding of matrix multiplication. Hill ciphers require the use of matrices that form boxes (2x2, 3x3, 4x4, ect.) although the most common are 2x2 and 3x3.
|