The subject of the Enigma cryptography machine is quite large and so has been separated into three sections, History of Enigma, Enigma Machine Details and finally Cracking the Enigma.
History of Enigma
The wartime cryptography machine known as Enigma was believed by the Germans to be a crucial component in their effort to win the war, in fact the opposite was to be the case.
In the period after the First World War, it became known that the Allies had broken the German encryption systems of that time. The breaking of these systems had led in part to Germany's defeat and to the entrance of the Americans into the war.
The German engineer Arthur Scherbius decided a new and far more secure cryptography system should be created. As an electrical engineer, Scherbius chose to implement the system in an electro-mechanical machine that was to become known as Enigma. The machine was simple in concept and yet the result was a system of great complexity.
Scherbius took out his first patent in 1918 but had a hard time selling his machines. He had imagined businesses would wish to communicate without their rivals being able to read their messages. However, due to the high cost of an enigma machine and a general lack of interest in securing their communications businesses did buy not them.
Nevertheless, in 1925 Scherbius finally found a market for his machines, the German military. By the following year Enigma machines were being mass produced and seeing service in the military and other Government organisations. The German military now had the most fearsome cryptography machine of the time at their disposal, it was a far cry from the amateurish systems in service a mere decade before.
Foreign governments attempted to crack Enigma when it first came into service, but all but the Poles gave up without any success. However, when the Second World War started in September 1939 the British suddenly faced a great need to crack Enigma. The story of how they succeeded in cracking Enigma by building on the work of the Polish is one of the great tales of World War Two. Ironically even with one of the greatest cryptographic devices in history the Germans faced the same situation as they had in the First World War, the Allies had been reading their secret messages and the war was lost.
For more about Enigma see the pages Enigma Machine Details and Cracking the Enigma.