The Enigma was one of the best of the new electromechanical cipher machines produced for the commercial market in the 1920s. Hugo Koch, a Dutchman, conceived of the machine in 1919. Arthur Scherbius first produced it commercially in 1923. Impressed by its security, which was based on statistical analysis, the German government acquired all rights to the machine and adapted it to the needs of its new, modern military forces. It became the standard cipher machine of the military services, of German agents, and of the secret police. It was also used at all echelons from high command to front-line tactical units including individual airplanes, tanks, and ships. An ordinary three-wheel Enigma with reflector and six plug connections generated the following number of theoretical coding combinations:

433,616,627,409,666,933,182,371,154,802,769,920,000, 000,000

That is roughly the same as 3.283  x 10114  .

Given this statistical capability, proper communications procedures and practices, and the fact that solving the Enigma on a timely basis would require rapid analytic machinery which did not exist, the Germans regarded the Enigma as impenetrable even if captured. The Germans, however, did not always practice proper communications security, and, more importantly, the Allies, even in 1938-39, were on the verge of creating the necessary cryptanalytic machinery which would unlock the Enigma's secrets. The evolution of this technology and its application were major contributing factors to the ultimate Allied victory in World War II.

A 3 rotor Enigma type M1070, circa 1926 . (E & T Museum photo)

A close up view of a disassembled Enigma rotor. (Photo by Jerry Proc)

This photo montage shows various Engima rotors in their storage cases. These examples are held by the Norwegian Armed Forces Museum in Oslo, Norway (Photo courtesy of Reidar Olsen, Norway. E-mail: trolok45@c2i.net )

Rotor contact detail from Serial A9949. (E-bay photo)
Rotor assembly detail from Serial A9949. (E-bay Photo)

enigma_basic instructions.jpg
Basic operating instructions from Serial A9949. (E-bay Photo)
Lid decal from Serial A9949. (E-bay Photo)
Plug board detail from Serial A9949. (E-bay Photo)

Front cover of manual.  (E-bay Photo)
Enigma M4 on display at the Canadian War Museum, Ottawa.  (Photo by Jerry Proc)

Tirptiz rotor. Note the five notches on the rotor rather the single notch in an Enigma K. (Photo by Mike Hillyard) 
Another Enigma 4 rotor variant called the "Tirpitz" was specially produced for shipping to Japan in order to enable secret communications between these two Axis powers during WWII. There are thought to be 9 surviving examples of the Tirpitz variant. There are two differences  between a regular Enigma and a Tirpitz variant  - a 5 notch rotor and no stecker board. The Tirpitz appears to be a 4 wheel rotor  but the left hand rotor is a UKW  (you set it rather than it rotating with the others). More Enigma Tirpitz photos here.
G-Enigma. This was a specially constructed machine which was supplied to some foreign governments friendly to Nazi Germany. (Photo by Vin Simmons)
Nigel West, an leading author specializing in security and intelligence issues, is also an Enigma collector and has this Wehrmacht three rotor Enigma in his collection.  He would be pleased to supply other Enigma photographs to anyone who needs them.  E-mail:  nigel(at)westintel.co.uk (Photo courtesy of Craig Longhurst)

Here is a  fine example of a pre-WWII built Luftwaffe Enigma machine (serial A6345 dated 1937) with the added benefit of three high-quality, matched, rotors and the Umkehrwalze D option. The German designation is Chiffriermaschine Gesellschaft  and it was made by  Heimsoeth und Rinke of Berlin. (Photo courtesy John Alexander, G7GCK Leicester, England.

The machine above carries serial number A6345 with matching serial numbers on all the rotors. Option Umkehrwalze (UKW) D is the unusual and rare part. Germany began to introduce the UKW D to make the Enigma even more complex and secure in 1944. A full description of the UKW D, by Philip Marks, can be found in CRYPTOLOGIA Vol XXV # 2  (Apr 01), Vol XXV # 3  (Jul 01) and Vol XXV # 4  (Oct 01) .

The importance of this UKW type is that it is re-wireable. Removing the outer case (a tight fit) reveals moveable plugs and their sockets. The UKW was introduced to the Luftwaffe and caused Bletchley Park some concern.  There is a special Enigma at BP even now - one specifically modified to tackle UKW D. Fortunately, German operators in the field did not like the hassle involved in using this additional part so its use never became popular.  See Museum Info section)

Enigma/NEMA type light bulbs (3.5v)  can be found with  250, 300, 350 and 400 mA ratings.  Most seem to be 300 or 350 mA.

A three rotor pre-war Enigma machine in operation.  The man using the machine is a Waffen-SS NCO. An Enigma weighs around 30 pounds without the carrying case and 35 pounds with carrying case. (Photo courtesy of Synder's Treasures, Bowie, Maryland).

This is no ordinary Enigma - this one's special because it is out in the open at the National Cryptologic Museum. Visitors can actually cipher and decipher messages and watch the machine in operation. A sign below the unit says "Please Be Gentle". (Photo by Jerry Proc)
Click to thymbnail to enlarge
enigma_uboat_intercept_s.jpg This is a reproduction of a teleprinter sheet of U-Boat message traffic intercepted during WWII by the "Y"  Service at Scarborough UK. 
enigma_keylist_3rotor_s.jpg Sample keylist for a 3 rotor machine. 
enigma_kbook_page_s.jpg A reproduction of the "K" Book, Kreigsmarine key settings for the Enigma machine. Printed with red, water-soluble ink on pink paper. 
All these documents are on display in the Communications and Electronics Museum in Kingston, Ontario. (All photos by Jerry Proc).
More Enigma info:
Enigma Story #1 - A Polish View
Enigma Story #2 - A French View
Commander Alec Dennis - The Man Who Captured the First Engima Code Books

References and Credits:

1) http://ed-thelen.org/comp-hist/NSA-Comb.html
2) Craig Longhurst,  Reading, Berkshire, UK;    e-mail: craiglonghurst(at)hotmail.com
3) Vin Simmons  < vinsimmons(at)aol.com>
4) M1070 photo   https://eandt.theiet.org/content/articles/2019/07/top-secret-from-ciphers-to-cyber-security-at-the-science-museum

 Back to Menu Page
Jul 17/19