Cryptonomicon Pontifex/Solitaire We're back to my favorite book for another round. We've done quite a bit with Cryptonomicon so far. One of my favorite moments is when Enoch Root introduces a cipher that two prisoners used to communicate using just a humble playing card deck. Drawing of the mine

A while ago, I explained in detail how to generate one time pad sheets [https://imapenguin.com/simple-unbreakable-encryption-with-a-pencil/] and use them to encrypt and decrypt messages. It turned out to be doable, only requiring a pencil and a way to create random numbers, but it's slow, error prone and tedious.

Hashes We did an implementation of a once popular hashing function in Part 8 on RC4 [https://imapenguin.com/making-and-breaking-ciphers-on-the-commodore-64-part-8-rc4/] without really going into why. A hash function is any function that is used to map data of an arbitrary size (input) to a fixed size output. An algorithm is

Recap So far we've * Reversed a string [https://imapenguin.com/cracking-codes-with-python-er-commodore-part-1/] * Shifted bits left and right (mostly right) [https://imapenguin.com/cracking-codes-with-python-er-commodore-part-2-the-shift-cipher/] * Brute forced a known simple cipher [https://imapenguin.com/making-and-breaking-ciphers-with-a-commodore-64-part-3-the-caesar-cipher/] * Channeled our inner John Connor by cracking ATM machines [https://imapenguin.com/making-and-breaki

Recap So far in this 8 part series on doing weird things with Ciphers on old computers we've: * Reversed a string [https://imapenguin.com/cracking-codes-with-python-er-commodore-part-1/] * Shifted bits left and right (mostly right) [https://imapenguin.com/cracking-codes-with-python-er-commodore-part-2-the-shift-cipher/] * Brute forced a known simple cipher [https://imapenguin.com/making-and-breaking-ciphers-with-a-commodore-64-part-3-the-caesar-cipher/] * Channeled our inner John