A simple Ruby implementation with lots of comments. This document explains how to implement DES, from the perspective of learning how the algorithm works. Simplicity and learnability are favoured over optimisation unlike most open source crypto code, so hopefully this will make it easier for people to understand and de-mystify DES and block-cipher cryptography in general. Code can be found here: http://github.com/chrishulbert/crypto How to Implement DES in Ruby

Thanks for reading! And if you want to get in touch, I'd love to hear from you: chris.hulbert at gmail.