The Enigma coding machine was a unique feature of the Wermacht during the war. All other forces used it also but the Kriegsmarine
Enigma coding tool was one of a kind.
Later the code breakers in Bletchley Park after months of trying, were able to break any message that was send out by
a submarine and any message that the BdU was sending out to the U-boats. This was the end of the German submarine force and
its famous Enigma coding tool.
The Enigma coding tool that was used by the Kriegsmarine had 2 versions.
The first one had the standard 3 rotor mechanics and the second one that had 4 rotor desing for extra protection and was
much more difficult to break than the original version.
The name of the second machine called "SHARK" and through the 4 rotor mechanism was able to encrypt to a level
that was astronomic the time it was build.
You can download the ENIGMA simulation tool for your own personal "fun". From the section you can download the Enigma
coding simulator and the Enigma simulator and the Enigma code book.