ABSTRACT
Throughout the history of human communication, the practice of keeping information secret by disguising it, known as cryptography, has been of great importance. Many important historical figures-for example, Julius Caesar, Francis Bacon, and Thomas Jefferson-have used cryptography to protect sensitive information. Before becoming the “Father of the Modern Computer,” Alan Turing played an integral role during World War II in the successful attacks by the Allies on the Enigma machine, which was used by the Germans to disguise information. Important literary figures have also included cryptography in their writings. In fact, William Friedman, called the “Dean of American Cryptology” on a bust at the U.S. National Cryptologic Museum, was first inspired to study the subject through reading Edgar Allan Poe’s short story “The Gold Bug.” Cryptography is also at the heart of some remarkably fascinating accounts from human history, such as the successful attacks on the Enigma machine by the Allies, and the Allies’ own effective use of Navajo code talkers during World War II. There are numerous books devoted exclusively to the history of cryptography, including excellent accounts by David Kahn [13] and Simon Singh [21]. However, cryptography is not just a historical subject. Most of us use cryptographic methods quite frequently, often without knowing or thinking about it, for example, when we purchase items using a credit card or send information using email.
