The
Enigma machines were a series of
electro-mechanical rotor cipher machines developed and used in the early- to mid-twentieth century to protect commercial, diplomatic and military communication. Enigma was invented by the
German engineer
Arthur Scherbius at the end of
World War I. Early models were used commercially from the early 1920s, and adopted by military and government services of several countries, most notably
Nazi Germany before and during
World War II. Several different Enigma models were produced, but the
German military models are the most commonly recognised.