Frequently Asked Question about Enigma
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On this page, I will try to answer a few FAQ's I received since I published my Enigma pages. I hope you find some answers or solutions to your problems here. If not, you can always
send me a mail.

Question: I have an Enigma message, but don't know the key settings to this message. Can you help me?
Answer: Unfortunately, no! You need the key settings for rotors, their order and ring settings, the start position of the rotors, the reflector and plugs. There are 107,458,687,327,250,619,360,000 possible keys! More about this number
at this page. An Enigma M4 is even harder to break. Breaking one single small message is almost a mission impossible. However, if you have vast computer power resources, the proper cryptanalytic techniques, and some luck, you could succeed. An example is Stefan Krah's M4 Project.

Question: I have problems deciphering your messages on another simulator, or vice versa.
Answer: First, check your Enigma settings. This simulator, unlike many others, 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: Does your software contain viruses, spyware or other nasty stuff?
Answer: No! There are far easier ways to send or download nasty stuff on people's computers. I've spend years of research on cipher machines, and months to write realistic sims. So why all that effort to send you a virus? I just want to share my passion for cipher machines. However, since early source code was freely available, you could encounter a bogus clone of this software elsewhere. The only official downloads and latest versions are available only on this website.

Question: Where can I see a real Enigma?
Answer: A list of museums and places where you can find Enigmas is available at Matt's
Wiki Crypto Tourisme site.

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?
: 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 have downloaded a new version of your software, and now have problems.
: 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 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, enciphered with Enigma, today?
Answer: That depends on the situation. If you have only one short message, say less than 50 letters, and you were to use that particular Enigma key setting only once, this would be rather secure. Don't forget that the number of possible keys on the Enigma machine is astronomical! Running through all possible keys would take a vast amount of time, even today. However, longer messages, and more messages with the same key would never stand against cryptanalytic attacks. That's how Bletchley Park did it, even without today's vast computer power. The CSG, Crypto Simulation Group, is breaking at this moment 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 critical information!

Question: I can't download and install the Enigma simulator?
Answer: Well, it should work. Others don't have problems. Did you read the readme file in the zip? Be advised that the sim only works on Windows, and some people have reported to me that my simulators also works under Linux with WINE with emulation software. If the download fails, you could try the alternative (identical) download from the preserved copies on the
Internet Archive. Frode Weierud or Tom Perera also host some of my software, but these might be previous versions. For the latest version, you should always download the sims from my website.

Question: Can I buy a real Enigma machine?
Answer: Yes! Many surviving Enigmas are now hot collector items (see my
links page). Prices range between 20,000 and 150.000 dollars or more, depending the model and condition. No, you can't buy one from me. You could buy a DIY Electronic Enigma-E , sold by the Crypto Museum for about 150 Euro.

Question: You must be a smart guy. Do you work for NSA?
Answer: Haha, no! Old cipher machines are just a hobby to me, just as writing software. Actually, most cipher machines are not that hard to understand and of rather simple construction. You don't need to be a genius or cryptologist. Anyone who sets his mind to it, and wastes enough time on it, can figure it out. Breaking cipher messages is another thing!

Question: Did you work with an Enigma during the war?
Answer: No! I'm not that old (thanks for the compliment) and never served in the German Army, I'm from Belgium. Neither was I employed in Bletchley Park, I'm not that smart (see question about NSA).

Question: Do you get rich, writing cipher machine software?
: Haha, No! There are several good freeware simulators on the net, so why bother asking money for it. History is here to share!

Question: How much work went into developing this simulator?
Answer: Don't ask my wife about it! The detailed information about Enigma was collected over a period of several years. Don't forget that information about the Enigma was very scarce before people like David Kahn, Frode Weierud or others who published their work on Cryptologia. The simulator itself took about a month to work properly, on and off in spare time and with additional research, but had a simple user interface. Two more months were required to produce a graphical correct and detailed machine, and to write a readable helpfile. Some years went by before arriving at the final version v7.0. This was only possible with the kind help of people like Tom and Frode.

Question: Do you have any other hobbies?
Answer: Don't ask my wife about it!

Question: Can I promote your site?
Answer: Yes! Although there's no financial benefit whatsoever, not for me and not for you. I'm always happy when I can share my passion with others. That's why I've created this site. You can put my main-page link on your website or mail the link to your friends.

Question: Where can I lean more about old cipher machines?
Answer: Start with the
crypto machines timeline and visit my pages on the U.S. KL-7, Hagelin machines, B-21, CX-52 and the various simulations.

Question: How can I make you happy?
Answer: If you enjoyed my website, sign my
guestbook or read the next question ;-)

Question: I still have a question. What do I do now?
: Don't hesitate to
e-mail me! Your questions and feedback are most appreciated. There are no stupid questions!

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Dirk Rijmenants 2004. Last changes: 20 April 2022

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