This repository explores classical cryptography, focusing on two major types of ciphers: Substitution and Transposition. The repository provides implementations and explanations for various cipher ...

Columnar Transposition Cipher Encryption and Decryption This is a Python program that performs encryption and decryption using the columnar transposition cipher. The key can be chosen randomly or ...

I hope you enjoyed Ed’s guest posts on NP-complete problems on TV the last couple of Mondays. It’s always great to hear from others on math that they are thinking about. This week it’s me again, and ...

We all have secrets to keep. Those secrets could be personal dirt we want to keep from others, or they could be something as mundane as our credit card numbers or medical histories. But all of us have ...

Abstract: Columnar transposition is a technique commonly used in text encryption to produce cipher text which is a permutation of its original text. In this study, the columnar transposition and ...

This was one of the most secure hand ciphers used in the Second World War. It was used by both the Allies and the Axis, and served both well. Its main weakness was that if the attacker intercepted two ...