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 ...

You can make a message secret in countless different ways. One common way is to use a substitution cipher, in which one letter is substituted for another. Another is to employ a transposition cipher, ...

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 ...

Introduction If you need to send a secret message to a friend, how could you prevent other people from reading it? One way is to encrypt the message—that is, use a secret code that only you and your ...