Machines of code and conflict
The centerpiece of the National Cryptologic Museum is its collection of German Enigma machines from World War II. The museum holds several of these electromechanical rotor cipher machines, including two that are fully operational and available for visitors to use. You can type a message on one machine, watch the letters light up on the lampboard, and then send the encrypted text to the other machine for decryption. One of the Enigmas in the collection was believed to have been used at one of Adolf Hitler's headquarters.
Alongside the Enigma is the only surviving U.S.-made Bombe machine. The Bombe was an electromechanical device, first developed by the British, designed to discover the daily settings of the Enigma machines. This massive machine, weighing over a ton, helped to significantly shorten the war by allowing the Allies to read German military communications.
The museum also shows the U.S. Army's SIGABA, a rotor-based cipher machine that was never broken by enemy forces during its service life. Developed in the late 1930s, the SIGABA was used for high-level communications throughout World War II and into the 1950s. Unlike the German Enigma, which had a relatively predictable rotor stepping motion, the SIGABA used a complex, pseudo-random system, making its code much more difficult to crack. By the end of the war, over 10,000 SIGABA machines were in use.
A library of secrets
The museum's library contains a collection of unclassified and declassified documents, papers, and rare books on the history of cryptography. Its holdings include volumes dating back to the 16th century. One of its most prized items is a 1518 edition of Polygraphiae libri sex by Johannes Trithemius, the first printed book on cryptography. This collection began in the 1930s as a research tool for the U.S. Army's Signal Intelligence Service, headed by William F. Friedman.
Exhibits extend beyond World War II, covering the American Revolution, the Civil War, and the Cold War. You can see displays on the Native American Code Talkers, who used their native languages to create unbreakable codes during both World Wars, and the story of the Zimmermann Telegram, a coded message whose interception helped push the United States into World War I. The museum also has exhibits on the women who made contributions to American cryptology, from the Revolutionary War to the modern era. Opened on December 16, 1993, it is the first and only public museum in the U.S. Intelligence Community and receives approximately 70,000 visitors annually.