Enigma was probably the most famous of the mechanical cipher devices used in World War Two, its fame assured by the feats of code-breakers at Bletchley Park who devised ways to uncover which of the possible 150 million million million ways the German armed forces were setting up the machine to conceal their secret communications – every day.
Scherbius’s original concept became available in physical form in 1923. Enigma machines are said to look a bit like typewriters, but that is a bit misleading because the wartime machines had no ability to print their output, having instead a panel of windows labelled A to Z under which one of 26 torch-bulbs would light up to show how a letter was enciphered. But Scherbius’s 1923 model didn’t look much like the kind of Enigma we are familiar with from World War Two: it really was like a typewriter, since it was designed to produce a typed document, but in cipher. Its rotors were concealed behind the keyboard, and were turned by special knobs that stuck out of the side of the machine.
