John F. Dooley

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...

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 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...