THE ENIGMA MACHINE:  A BRIEF HISTORY

     The theory behind the Enigma enchiphering machine first struck Albert Scherbius around
1918, when he considered the idea of building a cipher machine which used rotating rotors to
continually change the encoding context.  Scherbius immediately took his insights to the German
military, but was told that the Germans didn't require further code security as their code book
system had been sufficient during WWI.  Scherbius then opened his technology to the private
market, where its patents were ultimately acquired by Gewerkschaft Securitas. By the late
1920's, the Enigma machine was available commercially for individuals or companies who, for
one reason or another, required secure communication.  That initial offering did not implement a
plug board and used three rotors.
     The German Navy's interest in the Enigma machine was spurred by Great Britain's
announcement that they had cracked the German code book system.  The Navy begin purchasing
machines in 1925 and went to work modifying them to provide more security.  The German
Army quickly followed suit and within a year or two, the Enigma machine was the crux of
German military communication security.  The modifications that were made include the
addition of a plugboard and (in the case of the Navy) an additional rotor.  With this new
technology, the German military was confident that they had an unbreakable means of encoding
communications.
     Poland cryptanalysts first began their work on cracking the Enigma machine in 1927 and
despite Germany's various attempt to thwart their security attack by changing code regulations
and tweaking the machine, they were able to decode nearly all German messages by early 1939. 
It was later that year when German forces began attacking and ultimately invading Poland.  The
Polish cryptanalyst team fled to Britain to pass their research on to the Allied super-powers and
the German military went to work revamping their Enigma machines.  
     Using the work provided by Poland, Britain and the U.S. began their work on decoding
the messages of the (once-again revamped) Enigma machine.  Ultimately the Allied powers were
able to completely neutralize Germany's supposedly undecipherable security device by mid
1940.  More details of these efforts are provided later.


Additional Bibliography:


http://www.gvsu.edu/mathstat/enigma/timeline.htm

http://www.bonus.com/contour/Enigma_Machine/http@@/hops.cs.jhu.edu/~russell/classes/enig
ma/history.html