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 Messages, Mail, Notes or anywhere else you can type, and every letter is enciphered as you press it — the app you are in receives ciphertext, never the plaintext. A strip above the keys shows what you actually wrote, because the field itself never sees it. The rotors step as you go, and a reset key winds them back to the day's ground setting when you start a fresh message. SET IT LIKE AN OPERATOR Your key sheet holds a month of daily keys: rotor order, ring setting, ground setting and plugboard pairs, one row per day. Tap today's row and the machine is set, exactly as a signals clerk would have done from a printed sheet. WHAT'S HERE • The full machine: rotors I–V, reflectors, and a thirteen-cable plugboard • The Enigma keyboard, for enciphering inside any other app • A month of daily keys, generated from a seed you can share • Share sheet support to encipher text you have already written • Home Screen and Lock Screen widgets carrying the day's key • Shortcuts and Siri actions for enciphering and deciphering A NETWORK OF YOUR OWN Two people reading each other need the same key sheet, exactly as two operators needed the same printed one. Share yours by AirDrop, or hand it straight to a nearby device — it never touches a server, because there is no server. Whoever holds it can read you; nobody else can. Nothing you type leaves your phone.