These programs are implementations of classical ciphers in cryptology. An older version of this library was originally written for the Great Cipher Challenge 2020, a nationwide cryptology competition for students across the United States. Many more programs have been added to this open-source library in addition to the content displayed on the competition website at https://clubcryptology.wixsite.com/greatcipherchallenge/tools.
This library is a permanent work-in-progress! There are many ciphers that could potentially be added to this library that have not yet been implemented (e.g. double transposition, keyed Vigenere).
Programs are interactive, and almost every single program can be run individually.
If you have a suggestion for a cipher that could be implemented or a creative algorithm to solve a certain type of cipher, fill out this anonymous form: https://tinyurl.com/cipher-suggestions.
Sidenote: the following paper on the construction and cryptanalysis of multi-ciphers references many of the programs provided here: https://eprint.iacr.org/2021/1005