The Enigma

Arthur Scherbius designed the Enigma - a device which allowed businesses to communicate confidential documents without having to resort to clumsy and slow codebooks. The device consisted of many rotors turning on a common axis. The rotors had numbers 1 through 26 marked on the edge, or the alphabet A-Z, and were equipped with 26 electrical contacts (one for each letter of the alphabet) so that when a letter was pressed, the output would depend on the position of the rotor and its cross wiring. Within the same year, the Enigma was put to use; most famously by Nazi Germany before and during WWII.