Implementing Simplified Data Encryption Standard in Scala

(I intended for this blog post to be a full explanation of my SDES implementation, but it got too long too fast. Therefore, in this post I focused mostly on the binary number representation and didn’t analyze other topics such as the test suite and the class hierarchies, topics that I will maybe address in a future post —probably never)

Intro

DES is a symmetric algorithm for encrypting data. Simplified DES or SDES, as I will refer to it from now on, is a simple version of DES, which is used to familiarize the students with the inner workings of the algorithm without getting too involved with details. I happened to implement it for a semester course project and below are some of my thoughts.

Undestanding frog (by doing something else)

I will try to write a function to convert a bit-stream (in the form of a string) to its representation as an IPv4 address.

The catch is, the code must be as concise as possible.