"Success in dealing with unknown ciphers is measured by these four things in the order named: perseverance, careful methods of analysis, intuition, luck." So begins the first chapter of Colonel Parker Hitt's 1916 Manual for the Solution of Military Ciphers, a foundational text in the history of cryptology. An irrepressible innovator, Hitt possessed these qualities in abundance. His manual, cipher devices, and proactive mentorship of Army...