Historians believe that the inventors named the device after an orchestral musical composition by Edward Elgar entitled “Enigma Variations.” The encoding machines were first sold under the brand name “Enigma” beginning in 1923.
The device was used primarily by commercial industries during the 1920s, and some governments began to use it previous to and during World War II, the most notable of which was Nazi Germany.
The Enigma Machine was a rotor-based encoding machine that looked and operated similarly to a typewriter. Its purpose was to both scramble and de-scramble messages of a sensitive nature.
When a person types a message on the machine, a set of three rotors changes the letters so that the message becomes a scrambled, unreadable jumble of letters. The positions of the rotors serve as the scrambling and de-scrambling key to reading the encoded message.
With the correct rotor settings, a coded message entered into the Enigma Machine could also function as a simulator to recreate the original, readable message.