ABSTRACT
Cryptography has existed since the time people had secrets to keep or lacked confidence that their communication with another party would not be tampered with en route. Many accounts of the historical approaches to cryptography are captured in works like Simon Singh’s “The Code Book” [397] and David Kahn’s “The Codebreakers” [194]. While simply shifting characters in a message by a fixed amount, hiding a message on the previously shaven head of a messenger, or affixing a wax seal to a letter was sufficient (sometimes) at one time, those days are long gone. With the dawning of the digital age, reliance on the hope that the methods used to hide the secrets will not be discovered by those seeking to compromise those secrets is regrettably naive. Furthermore, while previously used techniques were at least partially reliable because they took a human being an inordinate time to break; today’s ubiquitous computing resources (including your cell phone) demand a much firmer foundation if secrets are still to be kept or message integrity is to be assured.
