Hill cipher cryptosystem is a linear algebra‐based classical polygraphic substitution cipher‐based technique. If the encryption key matrix (also called the key matrix) is not invertible, obtaining the ...

Does not support numbers, special characters. Key matrix should be invertible modulo 26.

In classical cryptography, the Hill cipher is a polygraphic substitution cipher based on linear algebra. Invented by Lester S. Hill in 1929, it was the first polygraphic cipher in which it was ...