In cryptology, the discipline concerned with the study of cryptographic algorithms, a cipher is an algorithm for encrypting and decrypting data. Transposition ciphers keep all the original bits of ...

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 ...

A stream cipher is an encryption method in which data is encrypted one byte at a time. In this method, a cryptographic key and algorithm are applied to each binary digit in a plaintext data stream to ...

The keys are correct as stated, but instead of numbering duplicate letters from left to right, Agent Madeleine numbered them from right to left. You may want to complete the decryption yourself before ...