My solutions to the Matasano Crypto Challenges (http://cryptopals.com/), implemented in Python 3.
If you haven't done them yet, and plan to do them at some point (which you totally should!), DON'T LOOK! That would be cheating and spoilers and all kinds of sadness.
(Note that the previous "no posting answers" honor code has been lifted, or else I wouldn't be publishing these at all :) )
Usage: pip install -r requirements.txt python test_cryptopals.py