In May 1917, William and Elizebeth Friedman were asked by the U.S. Army to begin training officers in cryptanalysis and to decrypt intercepted German diplomatic and military communications. In June 1917, Herbert Yardley convinced the new head of the Army’s Military Intelligence Division to create a code and cipher section for the Army with himself as its head.  These two seminal events were the beginning of modern American cryptology, the growth of which culminated 35 years later with the creation of the National Security Agency. Each running their own cryptologic agencies in the 1920s, the Friedman-Yardley relationship was shattered after Yardley published a tell-all book about his time in military intelligence. Yet in the end, the work they all started in 1917 led directly to the modern American intelligence community. As they got older, they became increasingly irrelevant in the burgeoning American cryptologic fraternity.  Topics and features: * Examines the lives of three remarkable and pioneering cryptologists * Offers fascinating insights into spies, codes and ciphers, rumrunners, poker, and military history * Sheds new light on interesting parts of the cryptologists’ careers—especially Elizebeth Friedman, whose work during World War II has just begun to be explored * Recounts several good stories, i.e., What if the Friedmans had gone to work for Herbert Yardley in his new Cipher Bureau in 1919? What if Yardley had moved back to Washington to work for William Friedman a decade later? This enjoyable book has wide appeal for: general readers interested in the evolution of American cryptology, American historians (particularly of World War I, the inter-war period, and World War II signals intelligence), and historians of—and general readers interested in—American military intelligence. It also can be used as an auxiliary text or recommended reading in introductory or survey courses in history or on the related topics.

When the United States declared war on Germany in April 1917, it was woefully unprepared to wage a modern war. Whereas their European counterparts already had three years of experience in using code and cipher systems in the war, American cryptologists had to help in the building of a military intelligence unit from scratch. This book relates the personal experiences of one such character, providing a uniquely American perspective on the Great War. It is a story of spies, coded letters, plots to blow up ships and munitions plants, secret inks, arms smuggling, treason, and desperate battlefield messages. Yet it all begins with a college English professor and Chaucer scholar named John Mathews Manly. In 1927, John Manly wrote a series of articles on his service in the Code and Cipher Section (MI-8) of the U.S. Army's Military Intelligence Division (MID) during World War I. Published here for the first time, enhanced with references and annotations for additional context, these articles form the basis of an exciting exploration of American military intelligence and counter-espionage in 1917-1918. Illustrating the thoughts of prisoners of war, draftees, German spies, and ordinary Americans with secrets to hide, the messages deciphered by Manly provide a fascinating insight into the state of mind of a nation at war.

The science of cryptology is made up of two halves. Cryptography is the study of how to create secure systems for communications. Cryptanalysis is the study of how to break those systems. The conflict between these two halves of cryptology is the story of secret writing. For over 2,000 years, the desire to communicate securely and secretly has resulted in the creation of numerous and increasingly complicated systems to protect one's messages. Yet for every system there is a cryptanalyst creating a new technique to break that system. With the advent of computers the cryptographer seems to finally have the upper hand. New mathematically based cryptographic algorithms that use computers for encryption and decryption are so secure that brute-force techniques seem to be the only way to break them - so far. This work traces the history of the conflict between cryptographer and cryptanalyst, explores in some depth the algorithms created to protect messages, and suggests where the field is going in the future.