21.5. History of Steganography

Stego is not a new field. As long as there have been people on the planet, people have needed to communicate without others knowing what they are saying (cryptography). There has also been a need to communicate without anyone even knowing you are trying to communicate (steganography). A very good book that covers the history of cryptography and to some extent steganography is called The Code Breakers by David Kahn.

21.5.1. Using steganography in the fight for the Roman Empire

Julius Caesar built the Roman Empire, and there were people who supported him and people who didn't. Caesar had to find a balance between making sure his enemies did not find out his secrets and trying to find out his enemy's secrets (a trend that is evident throughout history). Cryptography was important to make sure no one could read what Caesar was communicating to his allies, but the mere fact that he was communicating could have tipped his hand. Caesar's enemies had the same dilemma, and that's where stego came into play.