Enigma Machine
Simulate the Enigma, the electromechanical rotor cipher machine used by Germany in WWII. Choose three rotors (from the historical set I–V) and their order, a reflector (UKW-B or UKW-C), ring settings (Ringstellung), starting positions (Grundstellung), and optional plugboard (Steckerbrett) pairs. Type a message and the lampboard shows the encrypted output letter by letter, with the rotors stepping — including the famous double-stepping anomaly — exactly as the real machine did. Because Enigma is reciprocal (it's its own inverse), typing the ciphertext back through a machine set to the same starting position decrypts it. Everything runs locally in your browser.
Rotor setup (left → middle → right)
Message
Output
How it works: before each letter the rotors step, then the signal travels keyboard → plugboard → right rotor → middle rotor → left rotor → reflector → left rotor → middle rotor → right rotor → plugboard → lampboard. Each rotor is a hard-wired permutation of 26 contacts; the reflector is a fixed involution (it pairs contacts, so the path is symmetric), which makes Enigma reciprocal — the same machine setting encrypts and decrypts. The rotors turn like an odometer, but a mechanical quirk makes the middle rotor step twice when it reaches its notch position (the double-stepping anomaly), which breaks the simple odometer pattern. Two famous consequences the simulator honors: a letter never encrypts to itself, and encryption is its own inverse. This uses the historical rotor wirings (I–V) and reflectors (B, C) but toy-scale key management — real Enigma security depended on daily key sheets and the plugboard. Pairs with the Caesar, Vigenère, and Classical Ciphers tools. Everything runs locally — nothing leaves your browser.