I know that there is a formula to calculate the result of any input but is the logic of how the machine actually worked documented?

I have seen schematics for the circuitry and even a how to make your own at home site. But has the logic been broken down? Is there source for a virtua Enigma Machine that works by replicating the logic of the machine instead of just using the math?

  • $\begingroup$ Sorry to ask this, but did you try a web search via Google for "javascript enigma simulator"? The first hit (cryptomuseum.com) has many links to enigma simulation source code. For example, this one. $\endgroup$
    – Marsh Ray
    Commented Aug 3, 2011 at 20:08
  • $\begingroup$ This does have some interesting emulations. But I guess I was looking for more of an elegant and easy to follow solution rather than javascript. But this is at least someplace to start. $\endgroup$
    – Chad
    Commented Aug 4, 2011 at 16:13
  • $\begingroup$ Perhaps this is what you want: Simulator "A recurring theme in my Inbox is people asking for the enigma wheel wiring so that they can write their own simulator. To save repetition, this web page contains the information you will need if you want to build yourself a simulator." $\endgroup$
    – Marsh Ray
    Commented Aug 6, 2011 at 7:28

3 Answers 3


Is the logic for how the enigma machine worked documented somewhere?


If you're really interested in "diving in deeper" (pun intented), I would like to advise you to check out:

  • "The Cryptographic Mathematics of Enigma"
    Dr. A. Ray Miller
    NSA. Center for Cryptologic History. USA. 1996. 3rd edition 2002
  • "Funkpeilung als alliierte Waffe gegen Deutsche U-Boote 1939-1945."
    Arthur Bauer
    ISBN: 3-00-002142-6. The Netherlands, 1997. German. p. 33.
  • $\begingroup$ re the pun: groan $\endgroup$ Commented Jan 3, 2014 at 16:23

A great page with everything Enigma is Frode Weierud's CryptoCellar:


The main topic headings from the page:

  • Enigma Publications
  • Historical Documents
  • Cryptanalytical Documents
  • The Enigma Series
  • Decoding Projects
  • Patents and Manuals
  • General Information
  • Enigma Messages and Keys
  • Enigma Papers and Thesis
  • Enigma Simulators
  • Replica Machines
  • Enigma Links

The "logic" of the Enigma machine and the development of the Polish solution, in principle, are well described in David Kahn's "Seizing The Enigma". There may be better descriptions that have come out since, but I found this very clear and continue to recommend it. In addition to the nuts and bolts of the machine itself, Kahn describes the history from pre-war commercial tool to military tool, the creation of the reflector and additional rotors so that the 3 rotor tool could have both more transpositions and a larger mix of possible transpositions, and finally the addition of the 4th rotor position.

Crucially, he compares the security of different ways of using the machine, explaining why the German Navy's use of the same machine was harder for the British to break than the German Army or Air Force use. He describes the difficulties between the principle of the Poles' solution and the mechanics of an actual implementation, and provides a sketch of why Alan Turing's work was so important. He also points out how having a current German Navy code book, a present from the Soviets, allowed the British to realize what they were missing. The British made it their business to have the current Naval code book, meaning getting a new one every 6 months, for the rest of the war.

It was the confluence of all this work that allowed the comprehensive success of the effort to break Enigma. And, always, assisted by the over-confidence of the German authorities. Understanding how Enigma worked, including its logic and the logic of its use, shouldn't be separated from its complete failure in application.

"Seizing the enigma the race to break the German U-boat codes, 1939-1943" David Kahn Published 1996 by Arrow Books in London . Written in English. Edition Notes

Includes bibliographical references (p. [311]-326) and index. Classifications

Dewey Decimal Class 940.5485, 940.548641

Library of Congress DS810.C88 K34 1996

The Physical Object Pagination xii, 336 p., [16] p. of plates : Number of pages 336

ID Numbers

Open Library OL24935024M

Internet Archive seizingenigmarac00kahn

ISBN 10 0099784114

ISBN 13 9780099784111

OCLC/WorldCat 36209591


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