ENIGMA
One machine. Two directions. A different alphabet with every keystroke.
01 / Machine settings
All settings run left to right. A = 01. M4 includes the stationary Greek rotor first. Enigma I uses rotors I–V; M3 also supports VI–VIII.
Decryption requires the correct model, rotor order, rings, plugboard and message-start windows. This simulator does not crack unknown keys.
02 / Rotor windows & lampboard
Click a key to append a letter, or type in the message below.
Windows show the position after the entire message.
03 / Message desk
Prepared A–Z input
Every conversion starts from the configured starting windows. Encryption and decryption are the same operation: use the output as input with the same settings to reverse it.
04 / Five original historical examples
Four wartime transmissions and one original 1930 manual example. Load a card to apply its exact key and decrypt its message body.
Expected raw plaintext · source transcription
Operator’s notes
Paste only the encrypted message body, not radio headers, indicators or discriminant groups. Demo bodies are already prepared. For indicator procedures, decrypt the indicator with its prescribed settings first, then reset the windows to the recovered message key before decrypting the body.
Original Enigma preserves only A–Z, not spaces or punctuation. Decrypted historical text remains German telegraph text: X often separates sentences, Q may represent CH, and spelling errors or padding can remain. This page does not automatically translate or reconstruct spacing.
Natural-text preparation is a convenience, not a universal historical procedure: German umlauts become AE/OE/UE, ß becomes SS, other Latin accents are folded, digits are spelled in English, and . ! ? become X. Spaces and remaining non-A–Z characters are removed. This preparation is lossy; reversing the cipher recovers prepared letters, not the original formatting.