How to encrypt/decrypt with Enigma
We'll start with a step-by-step guide to decrypting a known message. You can see the result of these steps in CyberChef here. Let's say that our message is as follows:
XTSYN WAEUG EZALY NRQIM AMLZX MFUOD AWXLY LZCUZ QOQBQ JLCPK NDDRW F
And that we've been told that a German service Enigma is in use with the following settings:
Rotors III, II, and IV, reflector B, ring settings (Ringstellung in German) KNG, plugboard (Steckerbrett)AH CO DE GZ IJ KM LQ NY PS TW, and finally the rotors are set to OPM.
Enigma settings are generally given left-to-right. Therefore, you should ensure the 3-rotor Enigma is selected in the first dropdown menu, and then use the dropdown menus to put rotor III in the 1st rotor slot, II in the 2nd, and IV in the 3rd, and pick B in the reflector slot. In the ring setting and initial value boxes for the 1st rotor, put K and O respectively, N and P in the 2nd, and G and M in the 3rd. Copy the plugboard settings AH CO DE GZ IJ KM LQ NY PS TW into the plugboard box. Finally, paste the message into the input window.