Cryptography has become one of the basic enabling technologies of the internet as we know it today. Without the ability to transport such private information as credit card information, none of the commerce oriented sites from Amazon or EBay, none of the porn sites could exist. The net simply wouldn't be as we know it today.Much of the stories that we know of cryptology have to do with the breaking of the German Enigma or the Japanese codes from World War II. These codes would be trivial to break today. Faster more powerful computers, significant advances in the mathematical theory and techniques have made today's cryptography an entirely different animal.Dr. Oppliger's book draws a balance between the computer scientist approach who is looking to implement a secure communications protocol, and the mathematician who is interested in the theoretical concepts. This book does not presume to cover any of the many (sometimes conflicting) patent claims, nor the terribly confusing export regulations that are changing even faster than the cryptologic techniques.This is the state of the art in cryptography today at the conceptual level.