The National Museum of the U.S. Navy welcomed on 18 April 2017, the arrival of a four-rotor Enigma machine from the Cryptologic Command Display in Pensacola, Fla. The Enigma is on loan to be featured at the museum.

Enigma was a device used by the German military command to encode strategic messages before and during World War II. The Enigma machine was a device used to encrypt and decrypt secret messages. It was invented by German engineer Arthur Scherbius in 1918, and it was used extensively by the German military during World War II. The Enigma machine consisted of a keyboard, a set of rotors, and a lampboard. The user would type a message into the keyboard, and the rotors would scramble the message using a series of substitutions and transpositions. The scrambled message would then be displayed on the lampboard, which used a series of bulbs to represent the letters of the message. The Enigma machine was considered to be very secure because the rotors could be set in different positions, which changed the way the message was encrypted. This meant that the same message could be encrypted in millions of different ways, making it very difficult for anyone to decode the message without knowing the exact rotor settings. The Enigma machine was used by the German military to send and receive secret messages, including orders and military plans. The Allies were aware of the Enigma machine and its importance to the Germans, and they made a concerted effort to break the code. The Enigma code was first broken by the Poles, under the leadership of mathematician Marian Rejewski, in the early 1930s. In 1939, with the growing likelihood of a German invasion, the Poles turned their information over to the British, who set up a secret code-breaking group known as Ultra, under mathematician Alan M. Turing. Because the Germans shared their encryption device with the Japanese, Ultra also contributed to Allied victories in the Pacific. In 1941, a team of British codebreakers at Bletchley Park, led by Alan Turing, succeeded in breaking the Enigma code, which proved to be a major turning point in the war. Today, the Enigma machine is a fascinating piece of history, and it is remembered as a symbol of the ingenuity and determination of those who worked to break the code during World War II.