It's an overview of all the different types of encryption technology used throughout history and into today. Some of the technology covered: DES
Encryption, Electronic Code-Book/Cipher Block Chaining/Cipher Feedback/Output Feedback. Symmetric and Asymmetric Methodologies, Triple DES, IDEA, Blowfish, Skipjack, RC5 - WEP/WPA/WPA2/SSL/TLS - Hash
Functions -Public Key Infrastructure.