Cryptopals

These are my solutions to the Cryptopals Challenges.

This is a set of 48 practical programming problems that give you a hands-on crash course in understanding (and breaking) cryptographic ciphers. The problems are fun to do, and (most importantly) do-able. An excellent introduction can be found in Maciej Ceglowski's blog post.

The exercises are bundled in 8 sets:

1. Basics (1-8)
2. Block crypto (9-16)
3. Block and stream crypto (17-24)
4. Stream crypto and randomness (25-32)
5. Diffie-Hellmann and friends (33-40)
6. RSA and DSA (41-48)
7. Hashes (49-56)
8. Abstract Algebra (57-66)

Requirements

Python 3.10 or later.

Run pip install -r requirements.txt or do a conda install of packages listed in requirements.txt.

Tests

Many solutions have doctests. To run them all, run

python -m doctest challenge_*.py --verbose

Style

I ran all code through ruff and black. I generally also used typehints. Mypy didn't complain. The typehints may sometimes be a bit unwieldy since I often couldn't decide if I wanted bytes or string or integers as arguments, which would then lead to "Oh, what the heck, let's support them all."