Enigma G
The Great Secret Service German Abwher started using the Enigma G which one is also very popular as Zahlwerk Enigma. A very secure version with the gearbox to make rotors drive. The Wehrmacht take the Enigma D and revises it to Enigma I in 1932. This version of Enigma was the first which use the plugboard cables with the increases the space of keys enormously. This version which would become the famous as the German wartime cipher machine, but in the mid of 1932 the Polish Cipher Bureau (PCB) broken into the Enigma message traffic. And then their knowledges was turned to British and French cryptologists prior to invasion of Poland.