Enigma I rotor cipher machine with 3 rotors, in a box made of high-density plywood

The Enigma machine was developed in 1918 by Arthur Scherbius, but the German military had no interest in it. It was not until 1930 that the Reichswehr and the Kriegsmarine (the German Army and Navy) began to use Enigma, because their manual encryption processes had been broken during the First World War. Machine encryption, on the other hand, seemed secure. The Luftwaffe, the SS, the police, secret services, Reichspost, Reichsbahn, and the foreign office also used the Enigma machine. Altogether, the Germans used about 50,000 Enigma machines during the war.