Enigma I: Army Cipher

The Enigma I was the German Army's standard cipher machine, and the one Marian Rejewski first broke in 1932, years before Bletchley Park existed. Three rotors chosen from a set of five, a reflector, and a plugboard patched with up to thirteen cables — enough settings that its operators believed the traffic was unreadable. Enigma I is a working reconstruction, not an animation of one. Press a key and the rotors step, the circuit closes through the plugboard and the reflector, and a lamp lights. The wiring is the historical wiring. The stepping — including the double-step that so nearly hid a weakness — is the historical stepping. Encipher a message, reset to the same ground setting, type the ciphertext back, and the plaintext returns. That is not a trick; it is how the machine works. TYPE STRAIGHT INTO ANY APP The Enigma keyboard is how a message actually leaves this app. Switch to it in…