Modern Marvels - Season 8 Episode 16 Codes.

Whenever a culture reaches a level of sophistication in literacy, science, and language, codes spring up spontaneously. As the social life of a community increases in complexity, the demands for private communication between two or more people inevitably lead to cryptology–a system of secret symbolic messages. We explore the rich history of communicating with secret symbols–from Egyptian hieroglyphics to Caesar's encrypted directives, from WWI and WWII codebreakers to cyberspace.