The Romans didn’t have cybersecurity teams, but they’d already figured out that readable messages could be a problem.

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 ...

A letter can say one thing and mean something completely different.For centuries, that possibility mattered enormously. A messenger could be stopped. A ship car ...

April 12, 2012 Add as a preferred source on Google Add as a preferred source on Google In general, you want to avoid writing down sensitive information and just keeping it in your head but that's not ...

1. Introduction -- 2. From Julius Caesar to simple substitution -- 3. Polyalphabetic systems -- 4. Jigsaw ciphers -- 5. Two-letter ciphers -- 6. Codes -- 7. Ciphers for spies -- 8. Producing random ...