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Enigma Cipher Machine
This page is about the famous Enigma cipher machine, well known for the vital role it played during WWII. Below are descriptions of the various models, their manufacturers, some accessories, patents, computer simulations and codebreaking.

There is no such thing as the Enigma. In fact, Enigma is the brand name of a series of cipher machines, developed before and during WWII, some of which are compatible with each other, and some of which are not. If your are interested in the history of Enigma, you might want to check the Enigma Family Tree, the Enigma Timeline, or the Enigma Glossary.

Before and during WWII, Enigma has been the inspiration for many other designs of rotor cipher machines, like the British Typex and the American Sigaba. And even after WWII, some cipher machines were based on the same principle, such as the American KL-7, the Russian Fialka and the Swiss Nema.

If you own an Enigma machine, you may want to check our page about Enigma restoration materials.

We are always interested in acquiring new equipment, documents and other artefacts for the museum. If you have something to offer, please contact us.

 Enigma history
 Enigma family tree

Click here to view the Enigma Family Tree
Machines and accessories
Enigma C, the first lamp-based Enigma (Glühlampenmaschine) Enigma C The main Commercial Enigma machine on which all later models were based Enigma D Heeres Enigma (Wehrmacht and Luftwaffe) Enigma I Naval Enigma M4 (used by the U-Boats or the German Kriegsmarine) M4 Zählwerk Enigma A28, the predecessor of the Enigma G Zählwerk Zählwerk Enigma (Enigma G and Abwehr Enigma) Enigma G Enigma K, special versions of the Enigma D Enigma K Special version of Enigma K for the Swiss Army Swiss K
Enigma A, a printing Enigma (Schreibende Enigma) Enigma A Enigma B, another printing Enigma (Schreibende Enigma) Enigma B Enigma H, the final printing Enigma (Schreibende Enigma) Enigma H Enigma Z, the numbers-only Enigma Enigma Z Railway Enigma used by the German Reichsbahn Railway Enigma T (Tirpitz) used by the Japanese Enigma T Lückenfüllerwalze (configurable-notch wheel) Lf Umkehrwalze D UKW-D
Power Supply Unit PSU Enigma Uhr (also known as UhrBox) Uhr Schreibmax printer attachement Schreibmax Flat-faced Enigma lamps Lamps Breaking Enigma with the Polish BOMBA, the British BOMBE and the US BOMBE. Bombe

Related subjects
History History Working principle of the Enigma Theory Enigma wheel wiring Wiring Enigma family tree Tree Enigma timeline Timeline Enigma and Enigma-related patents Patents Real Enigma messages Messages Real wartime photographs of Enigma in action Photos
Enigma logo in various formats Logo Enigma simulators and replicas Simulator Reproduction stuff, such as batteries and lamp films Repro

Latest news

Working Principle
Many attempts have been made to describe the working principle of the Enigma machine on the internet. Some of these are correct, and some are not. This is yet another attempt.

Several years ago, when creating the Enigma-E, an electronic replica of the Enigma, we had trouble understanding the precise operating principle of the Enigma machine; something that is vital for a reliable simulation. At the time, most websites only gave a rough description of the machine and important details were omitted. We then created out own description and made it publicly available.

 More information
 Wheel wiring

If you are interested in building your own electronic Enigma machine, you might want to learn more about the Enigma-E self-build kit. It is compatible with a real Enigma machine.

Enigma models
Before and during WWII, many different Enigma machines were developed and built. Some of these machines are compatible with each other, but others are not. Below is a list of some of these machines that we've seen over the years. Please note that this list is by no means complete and will be subject to future changes, as and when we find 'new' machines. Each machine is described briefly below. Click the image for a full description with many photographs.
Enigma I
The Enigma I was developed especially for the German Reichswehr (later: Wehrmacht) and forms the basic design on which all German Army Enigma machines are based. Is has three moving wheels, a fixed Reflector (Umkehrwalze, UKW) and a plug board (Steckerbrett).

The Standard Naval Enigma (M3) is functionally identical to this machine, but has letters on the wheels rather than numbers.

 More information
Enigma I with top lid and flap open

Enigma M4
On 2 February 1942, the Kriegsmarine (German Navy) suddenly introduced this new version of the Enigma machine. The M4 had 4 wheels instead of the usual 3 and caused great upset with the allied codebreakers.

The M4 was used exclusively by the U-Boot division of the German Navy. The rest of the Navy kept using the M3.

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Zählwerk Enigma A28
At some point in the Enigma family tree, a machine was developed with an improved wheel-turnover mechanism and a counter. It was called the Zählwerk Enigma and was used by various intarnational commercial and military customers.

The later Enigma G (model G31) was based on this Enigma model.

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Enigma G
The Enigma G (model G31) was a slighly smaller variant of the Zählwerk Enigma (see above). The machine was sold to various international customers and was also used by the German Secret Service, the Abwehr, during WWII.

The machine is sometime referred to as the Abwehr Enigma although this name is actually incorrect. The machine was used by other customers as well and the Abwehr also used other machines than the Enigma G.

 More information
Close-up of Enigma G

Enigma D
The Enigma D was developed in 1926 as the successor to the Enigma C. It is often referred to as the Commercial Enigma. The official model number was A26 and it was given the internal designator Ch. 8.

The image on the right shows a rare sample of the Commercial Enigma that was found in 2011.

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Typical view of Commercial Enigma with serial number A818

Enigma K
The Enigma K can be regarded as a series of 'special' machines based on the design of the Enigma D. The official model number is A27 and the first internal designator for this machine is Ch. 11b. The machine was introduced in 1927, but it wasn't before 1936 that the letter K was used in the serial number.

Other machines, such as the Tirpitz (T), the KD and the Swiss K, belong to this family.

 More information
A view at the wheels. The leftmost wheel is the settable reflector (UKW)

Swiss K
The most famous version of the Enigma-K is the one that was produced during WWII especially for the Swiss Army. For this reason it is often called the Swiss-K. It was modified by the Swiss Army and was supplied with an external lamp panel and a power supply.

As the Swiss knew that the Germans were reading the Swiss Enigma traffic, they designed the NEMA as a replacement.

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The contents of the wooden box. The Enigma-K at the left and an additional lamp panel at the right.

Enigma KD
The Enigma KD was a rare variant of the Enigma K, that was used by Mil Amt, the successor of the Abwehr. It is based on the Enigma K but has wheels with 9 notches each, plus a rewirable reflector (UKW-D).

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Railway Enigma
During WWII, the Germans used a special Enigma machine for the German Railway (Reichsbahn). It was basically a standard Enigma K with rewired wheels and a rewired UKW.

Enigma traffic from the German Reichsbahn was first encountered by the codebreakers at BP in July 1940 and later in February 1941.

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Commercial Enigma machine used by the German Railway (Reichsbahn)

Enigma T (Tirpitz)
The Enigma T, codenamed Tirpitz, was developed during WWII by the Germans especially for use by the Japanese Army. It was based on the commercial Enigma K, but had differently wired wheels and multiple turnovers on each wheel. Furthermore, it had an Eintrittswalze (ETW) that was wired differently than all other Enigma machines.

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Enigma A
In 1923, the first machine under the Enigma brand appeared on the market. It was the Enigma A that was large and bulky. It resembled an electric typewriter and printed its output directly on paper.

Although we've never actually seen the machine, and therefore have no good photographs available, we did find an accurate description of the machine by Arthur Scherbius himself.

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Enigma B
The Enigma B was developed in 1924 as the successor to the Enigma A. The rotating print head of the Enigma A was replaced by a series of type bars, like the ones commonly found on typewriters.

The machine looks very similar to a standard typewriter and is very well finished. Nevertheless, there were many production problems and it appeared very difficult to operate it reliably at higher printing speeds. In 1926 it was replaced by a modified and improved version, which probably looked similar to the 1924 model.

Eventually, in 1929, it was replaced by the Enigma H (see below) which was far more bulky.

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Enigma H
The Enigma H was the last model in the range of Schreibende Enigma (printing Enigma) machines. It was developed and introduced in 1929, as the successor to the Enigma B.

The official model number for this machines was H29 and the internal designator was Ch. 14, whilst it was called Enigma II by the Reichswehr (the predecessor of the Wehrmacht). This machine was sometimes used as a printer for a modified Enigma I or Enigma G.

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Enigma C
The Enigma C was the first machine that used light bulbs (Glühlampen) for its output. It was introduced in 1924 as a lower-cost alternative to the large and bulky typewriter-style machines such as the Enigma A.

The letters on the keyboard and on the lamp panel are organised in the order of the alphabet.

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Enigma Z
The Enigma Z is a rather strange variant of the light bulb machine (Glühlampenmaschine) as it only has 10 keys and 10 lamps, containing the numbers 0 thru 9.

Not much is known about this machine, although it is likely that there were two different versions of it; one based on the Enigma D and the other based on the Zählwerk Enigma (G).

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Umkehrwalze D
During WWII, some attempts were made to make Enigma traffic more secure. In January 1944, a field-rewirable reflector, called UKW-D, was introduced by the Luftwaffe (German Air Force).

It is little known that an UKW-D was also developed for the Kriegsmarine (Navy). The UKW-D shown here is such a rare naval variant.

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Enigma Uhr
In another attempt to make the Enigma more secure, the Luftwaffe introduced the Enigma Uhr in July 1944.

It was a small wooden box that connected directly to the Steckerbrett of the Enigma by means of 20 cables. With a large wooden knob, the operator could quickly select any of the 40 available alternative wirings.

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Lückenfüllerwalze   wanted item
Another measure to make the Enigma safer, was the so-called Lückenfüllerwalze (gap-fill wheel) that featured 26 user-configurable notches. This way, the number and position of the notches of each wheel could be changed frequently.

The Lückenfüllerwalze was planned to be used in combination with UKW-D, but like UKW-D and the Uhr it came too late.

 More information

Power Supply Unit
The Power Supply Unit (PSU) shown here is very rare and was used with the Enigma K machines supplied to the Swiss Army and the Swiss Foreign Office. It can be connected to a variety of mains voltages and has output terminals for 4 Enigma machines.

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Schreibmax printer
For convenience a small printer was developed for Naval Enigma machines. They could be fitted on top of an M3 or M4 machine and had an external power supply unit.

When typing, the (de)ciphered text was printed on a 9mm paper strip.

 More information
Enigma M4 with Schreibmax

Enigma Patents
In 1918, the first Enigma-related patent was registered by Arthur Scherbius in Germany. Since then, numerous other inventions have been patented by Scherbius and his collegues, in Germany as well as in many other countries.

We've collected the most important Enigma-related patents on a single page, which are also available for download.

 More information

In recent years, some real Enigma messages have been recovered from the archives and from sunken U-boats and attempts have been undertaken to break these messages again.

This section of the website deals with some real Enigma messages, complete with the required settings of the machine, so that they can be decoded on a simulator.

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Enigma Lamps
An Enigma machine uses small - rather unusual - lamps for its output. These lamps have a common E10 fitting, but have a somewhat flattened glass bulb. It is important to find these lamps, as ordinary bulbs are too high and will penetrate the celluloid lamp film. There are two variants: clear and half-opaque.

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Reproduction stuff
Many Enigma machines found today, are not in very good condition and may require some work in order to get them going again.

In the past few years, various people have made an effort to produce good and accurate reproduction parts in order to restore Enigma machines. Some of these parts are available through the Crypto Museum.

 More information

Enigma Family Tree
Based on many years of research by Frode Weierud, we've been able to put together the most accurate family tree of Enigma machines to date. It shows the relationship between the various models and variants, and provides a lot of additional information.

Please note that the tree is based on ongoing research and is therefore subject to changes in the future.

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Breaking Enigma
It is sometimes thought that the Enigma was broken by Colossus, the first electronic digital computer. This was not the case, however.

The Enigma was broken manually (using hand methods) and with help of an electro-mechanical device, called the Bomba (Polish), and Bombe (British). The latter has been rebuilt and is now on public display at Bletchley Park (UK).

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Enigma Manufacturers
Initially, Enigma machines were manufactured by the original company Chiffriermaschinen AG (Aktiengesellschaft) in Berlin (Germany). After the Germans acquired the Enigma patents, the name of the company was changed to Heimsoeth und Rinke and other companies were appointed to manufacture Enigma machines under license. Below is the complete list of Enigma manufacturers [1] with their official manufacturer's code (except for the original manufacturer, who is listed first).
Code Issued Name Address
- - Chiffriermaschinen AG Steglitzerstraße 2
Berlin W 35
aye Oct 1940 Olympia
Büromaschinenwerke AG
bac Feb 1941 Ertel-Werk
für Feinmechanik
Westendstr. 160
gvx Jul 1941 Konski & Krüger
Fabrik elektr. u. mechanischer Apparate
Chausseestr. 117
Berlin N 4
jla Sep 1941 Chiffriermaschinengesellschaft
Heimsoeth und Rinke
Uhlandstr. 136
jmz Sep 1941 Atlas-Werke AG
Steinhöft 11


    1. Document kindly supplied by Arthur Bauer [2].
Enigma logo
Below are digital copies of the original Enigma logo. This logo has been recreated from scratch and is presented here as a PDF file, in order to preserve the resolution. The copyright of this logo belongs to us. You may download and use these logo's for your own - non-commercial - personal use. For commercial use of the logo, please ask permission first.   
Enigma Replicas
Every now and then, someone decides to built a replica of an Enigma machine. Although the basic operating principle of the machine is pretty straightforward, making a reproduction is not an easy task. Bear in mind that a single coding wheel consists of over 300 individual parts! Below are some links to people who have successfully created a replica.

Relatives of Enigma
Enigma is arguably the first comercially successful implementation of the rotor-based cipher machine. As its patents were registered in many parts of the world, its design has been copied numerous times. Many of the later machines, including the machines used by the Allied Forces during WWII, were largely based on the design of the Enigma. Here are some examples:

Enigma Simulator for Windows
In 2004, Dirk Rijmenants in Belgium released the first version of his graphical Enigma simulator for Windows. With this program he won the Superior Coding Award in the 2004 Planet Source Code Contest (PSC). Since then, the program has been enhanced several times and is currently considered one of the best Enigma Simulators available for the Windows operating system.
Version 7.0.1 now available  
Updated 7 December 2011.

The program simulates all known Enigma variants in great detail, including appropriate skins and sound. Operation of the simulator is very intuitive and online help is available at a click of the mouse. The image on the right shows a screen-shot of the M3 simulator.

 Download simulator (off-site)

Other simulators, and simulators for other platforms, are listed below.

Enigma Simulators
In the past few years, a number of Enigma computer simulations have been developed for a variety of platforms. Below is a list of popular Enigma simulations. Click any of the links, or click the logo of your favorite operating system below.

Mac OS X Mac OS X Windows Windows RISC OS RISC OS Perl Perl Java Java PalmPilot PalmPilot Flash Flash

  1. Oberkommando des Heeres,
    Liste der Fertigungskennzeichen für Waffen, Munition und Gerät

    Reichsdrückerei Berlin 1944, reprinted by Pawlas, Nürnberg, 1977.
    ISBN 3-88088-214-2

  2. Arthur Bauer, Foundation for German Technology
    Historical Enigma documents kindly supplied for reproduction.

Further information

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