Cryptobin

Over the holidays I spent some time on two different but related sets of challenges.

The first was the Krypton wargame at OverTheWire. This wargame goes over some basic classical cryptography. I was a bit disappointed in the last level, I don’t think the way I solved it was the intention of the author. It certainly didn’t match the level text.

The second was the AIVD kerstpuzzel, which is an annual Christmas puzzle produced by the Dutch equivalent of the CIA. This year’s edition was particularly difficult (at least, this is what I read online). There was some cryptography, word puzzles, number sequences, and a lot of pattern recognition. I didn’t get very far.

I want to do better on next year’s puzzle. A lot of the problems seemed ripe for automation. Certainly there was a lot of general functionality needed to implement solvers for specific problems. After I gave up on the puzzle, I decided to implement my solutions to Krypton in a useful way. It was also a good excuse to become more familiar with python.

Enter cryptobin.

Right now it’s just a loose collection of utilities. I have two desires for this project. One is to provide command line utilities for common classes of problems. The other is to provide a large collection of useful python modules, in order to quickly hack together solutions for more specific cases.

I see several categories of tools:

• classical cipher utilities, including plaintext analysis for automation
• advanced dictionary search utilities
• number sequence tools (this one is more difficult, but at the very least a tool that pulls in all of the relevant information for each number)
• whatever else I can automate

Since I keep coming back to wargames and puzzles, this is one project I expect I’ll be able to maintain.