On this page some frequently asked question we received since we published the Enigma pages and the Enigma simulator. We hope you find some answers to your question or solutions to your problems. If not, you can always send an mail.

Question: I can't install the Enigma Sim.
Answer: It should work. Others don't have problems. Did you read the Readme in the Zip file? The readme explains the installation in detail and provides tips to solve installation problems. The Enigma Sim works on Windows, and also with WINE on Linux, and with Parallels Desktop on MAC.

Question: I have downloaded a new version of your software, and now have problems.
Answer: Did you uninstall the previous version? It's better to do so. Just go to the Configuration screen, select Software and search for Enigma. Next, hit the Add/Remove button. When the old version is gone, install the new one.

Question: I have problems deciphering your messages on another simulator, or vice versa.
Answer: First, check your Enigma settings. This simulator, unlike some other simulations, is fully compatible with the real Enigma. If you haven't made an error while setting up the machine, or a deciphering error, the other sim probably works incorrectly. There's a lot of software on the web that doesn't work like the real thing. Some other correct working simulators, also fully compatible, can be found on Frode Weierud's or Paul Reuver's websites, or you can use Andy Carlson's online Enigma Applet. They all work just like the real thing. Again, double check all your rotors, their order and ring settings, the start position of the rotors, the reflector and plugs. Many Enigma novices forget one of these during enciphering or deciphering.

Question: I opened the lid on the Enigma simulator, to change some rotors, and I can't close it again.
Answer: There's no problem with the program! Did you click the handle in the upper left corner of the rotor area? If you did click it, and the lid still doesn't close, there are some rotors missing in the machine. All three (Wehrmacht) or four (Kriegsmarine) rotors must be in place before you can close the lid. The rotors, used in the Enigma, are at the top of the machine, not to be mistaken with the box with spare rotors, shown at the bottom of the machine. Once you inserted all required rotors, you can close the lid by clicking the handle.

Question: I want to send Enigma messages to my friends, how do I set up my machine?
Answer: To communicate with others, you need to agree on the key settings of the Enigma. You will have to create a key sheet and distribute it amongst your friends. You can use my Enigma Codebook Tool to generate key sheets.

Question: My friend and I both have the Codebook Tool. If we enter the same date, the Tool generates different keys!
Answer: Of course! Each generated code sheet is unique and cannot be reproduced. If anyone could produce the same code sheet again and again, it would not be secret anymore! The program isn't a codebook, it generates unique codebooks. Once a codebook is generated, one has to distribute the codebook text file or a printed version amongst the users. A program that would generate the same key over and over, would compromise the secrecy of the keys.

Question: Where can I find more authentic Enigma messages?
Answer: Authentic messages are very rare! CSG, the Crypto Simulation Group, is occupied with breaking over 500 original authentic German messages that survived the War. Some of them are available on Frode's website and will also become available on Cryptologia. Two authentic Kriegsmarine M4 messages are available, thanks to Stefan Krah's M4 message breaking project. Another nice way to test you codebreaking skills is the Enigma Cipher Challenge.

Question: I think there's a problem with the middle rotor. Sometimes, it steps on two successive keystrokes.
Answer: That's normal! This is the famous "double step", caused by the systems of pawls, ratchets an notches. The pawls are engaged on each keystroke, but only advance the next rotor if they can fall into the previous rotor notch. This happens once in 26 steps. However, during this event, the pawl drops into the notch, and not only grabs the next rotor ratchet, but since the pawl is in the notch, it will also push the notch rotor one step further. Of course, this only appears with the middle rotor. The first, rightmost , rotor always steps, and the third doesn't use its notch.

Question: Why is it so hard to set up the Enigma simulator, opening cover, changing rotors, plugs and so on?
Answer: Because the Germans didn't have computers, Windows or easy program menus. They only had that electro-mechanical machine in a wooden box. You wanted a simulation, right?

Question: If I use the four rotor version, the fourth rotor doesn't step. Is there a problem?
Answer: No! The answer is quite simple. The four rotor Enigma is derived from the three rotor version. The only changes were a thin reflector and fourth rotor, which took the same space as a normal wide reflector, and a little window to view the fourth rotor. That's all! They didn't adapt the rotor advance mechanism or add a fourth pawl. They just believed this wasn't important. The fourth rotor would only step once every 17,576 keystrokes. From the cryptanalysts point of view, the fourth rotor increased the number of keys by 26, the number of possible positions, set by hand.

Question: What is the purpose of the Kenngruppen in Enigma messages?
Answer: They were used to tell the receiving operator which key was used. More information is found on my Enigma Procedures page.

Question: Why does the Enigma Codebook Tool only produce 10 and not 13 plugs or Steckerverbindungen?
Answer: The answer is simple. The Germans only provided 10 cables with each machine, and a few spare cables attached in the case cover.

Question: How secure is my message, when enciphered with a real Enigma or simulator?
Answer: If you only encrypt one short message with less than 50 letters, and use that particular Enigma key setting only once, this would be difficult to break, but still possible. Running through all possible keys would take a vast amount of time, even today. However, current cryptanalytic algoritms on modern computers can break the message in a short time. The CSG Crypto Simulation Group has succesfully broken a large number of original authentic German messages. More info on Frode Weierud's website. Today, I strongly suggest never to use the Enigma to protect sensitive information!

Question: Can I buy a real Enigma machine?
Answer: Some surviving Enigmas are now collector items. However, prices ranged from $20,000 in the 1990s to $400.000 dollars and more in recent years, depending the model and condition. You could buy a DIY Electronic Enigma-E from the Crypto Museum for about 150 Euros.

Question: I still have a question.
Answer: You can send an e-mail. Your questions and feedback are appreciated.