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 ...

Introduction to ciphers and substitution. Alice and Bob and Carl and Julius: terminology and Caesar Cipher ; The key to the matter: generalizing the Caesar Cipher ; Multiplicative ciphers ; Affine ...

It’s been a couple of Math Mondays since we last looked at columnar transposition ciphers, so let’s jump back in. In the It’s been a couple of Math Mondays since we last looked at columnar ...

Before we move into the meat of this article, let’s define a couple terms related to cryptography. The syllable crypt may make you think of tombs, but it comes from a Greek word that means “hidden” or ...

Introduction: A revolutionary cipher -- Cryptology before 1500: a bit of magic -- The black chambers: 1500-1776 -- Crypto goes to war: the American Revolution -- Crypto goes to war: the American Civil ...