The message is called the plaintext because it is the unchanged source information. Example: The cat ran away. The secret message generated is called a cipher or ciphertext and it is the encrypted ...

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 ...

Learn how to implement a classic substitution cipher in C! This step-by-step tutorial walks you through encoding and decoding messages by replacing each letter with another according to a fixed key. A ...

Hannah handed me a piece of paper with the following string of letters. “Each letter stands for another one,” said Hannah. “Ooh, a substitution cipher!” I thought. But I was stumped. “Is this just one ...