Schlüssel M · 4-Rotor Naval Cipher Machine
Walzen — Rotors & Ring Settings
Glühlampenfeld — Lampboard
Tastatur — Keyboard
Funkspruch — Message
Lochstreifen — Paper-Tape Puncher
Steckerbrett — Plugboard
Tap the machine keys or press A–Z for live, one-key encoding — or type a whole message in the box and hit Enter to watch it clatter through. Encoding is reciprocal: feed the ciphertext back with the same start settings (use Clear Tape to re-seat them) to decode it.
Authentic 4-rotor Kriegsmarine M4 behaviour: real rotor wirings (I–VIII, Greek β/γ) and thin reflectors, proper right-hand stepping with the double-step anomaly. The thin Greek rotor is settable but does not rotate while typing, exactly as on the original. The tape is punched in 5-bit teleprinter code (ITA2) with the letter printed above each column.