# Simple hill cypher - using matrices to create a coded message.

Victor Van Der Helm & Victor Vildé

Simple hill cypher

Nowadays people like keeping  things secret and secure, this is most commonly done with cryptography. This is not only used for emails, and instant messages, it can also be used for good old fashion letters in which the people communicating have a legend to decrypt the message sent.

Encryption is the transformation of data into some unreadable form. Decryption is the undoing of the encryption to be able to read the message in some simple form. Normally when you encrypt something, you would most commonly have “units” substituting your letter or sentences. The units could be in one's, two's or even three's. There are various ways of substitution cyphering, one way (the most common way), would be to use ROT13, an alphabet rotated over 13 steps.

Simple Hill Cypher, is a method to solve and encrypt a  message. The method consists of using substitution. Eg:

Next we would convert the message into a 3X1 matrix.

9        9        0        20

0        11        13        8

12        5        1        21

We would then multiply this matrix with the encoding matrix to incode it:

1        0        0

0        2        0

0        0        2

This would be your encrypted message: [M] [E] = encrypted matrix

The receiver would use his mathematical skills to solve the equation, than the answer.

[E] X[M] = ...