Chaocipher: Javascript and Python versions

Description

Chaocipher is a method of encryption invented by John F. Byrne in 1918 that was never publicly solved.

The algorithm was published in May 2010. These implementations are based on a paper by Moshe Rubin.

Usage

Javascript:

Load the chao.html in a browser. Enter the left and right alphabets. Enter either the plaintext or the ciphertext and click "Encrypt" or "Decrypt" respectively.

Python:

The python program chao.py reads the plaintext or ciphertext from standard input and writes the result to stdout. The left and right alphabets are set using the --left and --right arguments respectively. The --encrypt and --decrypt arguments specify the mode.

An example of encrypting a file: cat myfile | ./chao.py --encrypt --left HXUCZVAMDSLKPEFJRIGTWOBNYQ --right PTLNBQDEOYSFAVZKGJRIHWXUMC

An example of decrypting text entered from the terminal: ./chao.py --decrypt --left HXUCZVAMDSLKPEFJRIGTWOBNYQ --right PTLNBQDEOYSFAVZKGJRIHWXUMC