Enigma machine: the device that changed WWII

by Cristian Gal / 23 July

The Enigma machine is the creation of dr. Arthur Scherbius. This device was capable of transcribing coded information for secure communications. In 1923 he set up his Chiffriermaschinen Aktiengesellschaft (Cipher Machines Corporation) in Berlin to manufacture this product.

The German military however was producing its own version. The German navy introduced their version as well in 1926, followed by the army, in 1928, and the air force, in 1933.

The military Enigma version allowed an operator to type in a message, then scramble it by means of three to five notched wheels, or rotors, which displayed different letters of the alphabet. The receiver needed to know the exact settings of these rotors in order to reconstitute the coded text. The Poles managed to crack the commercial Enigma versions by reproducing the internal parts of the machine, but that was not useful for decoding the military versions.

During the World War II, the military versions of Enigma were heavily used by the Germans, convinced that it couldn’t be decoded. The allies established a special divison at Bletchley Park, Buckinghamshire, whose task was to decode the German communications. The best mathematicians were recruited here and, with the intelligence from the Poles, they build early computers with the task to work out the vast number of permutations in Enigma settings. In the mean time, the Germans were upgrading their machine by improving the hardware used for setting the code in each machine. Also, the use of daily codes for the machine made the allies’ job a lot harder.

One of the briliant mathematicians involved in decoding Enigma was Alan Turing.

Born in 1912, in London, he studied at Cambridge and Princeton universities. Turing played a key role inventing, along with fellow code-breaker Gordon Welchman, a machine known as the „Bombe”. This device helped to significantly reduce the work of the code-breakers.

From mid-1940, German Air Force signals were being read at Bletchley and the intelligence gained from this was quite helpful. From 1941, messages sent using the army’s Enigma were read also. The one used by the German navy, on the other hand, was not that easy to crack.

Capturing Enigma machines and codes from different German units helped decipher communication, but with a considerable delay. To compesate for this, allies started hunting for ships and planes that carried Enigma codes in order to decode communications faster.

In July 1942, Turing developed a complex code-breaking technique he named „Turingery”. This method helped the team at Bletchley understand another device that enciphered German strategic messages of high importance – the „Lorenz” cipher machine. Bletchley division’s ability to read these messages contributed greatly to the Allied war effort.

Alan Turing’s legacy came to light long after his death. His impact on computer science was widely acknowledged: the annual „Turing Award” has been the highest accolade in that industry since 1966. But the work done at Bletchley Park – and Turing’s role there in cracking the Enigma code – was kept secret until the 1970s. Actually, the full story was not known until the 1990s.

It has been estimated that the efforts of Turing and his fellow code-breakers shortened the war by several years. What is certain is that they saved countless lives and helped determine the course and outcome of the conflict.