A combination of mechanical and electrical subsystems, named Enigma Cipher Machine and invented by the German engineer Arthur Scherbius, was used to encode strategic messages before and during World War II. But it is not the only scientific contribution inventors or scientists did during this period of time. This led to a series of inventions and research that laid the groundwork for important nowadays technologies.
Enigma code was first broken by the Polish, under the leadership of mathematician Marian Rejwski and soon sent the information to the English, who quickly set to work by bringing together the masterminds of the time in London and setting up a secret code-breaking group named Ultra under the leadership of Alan Turing and conformed by Hugh Alexander, Joan Clarke, Gordon Welchman and Stuart Milner-Barry.
Alan Turing is considered the father of Artificial Intelligence and the machine that he invented to decode Enigma was the pioneer of what years later we would call ‘computers’.
How did Enigma work?
Looking like a typewriter that used battery-powered. A cipher clerk typed a message in German, letters were illuminated one by one on the lamp board while an assistant recorded the letter by hand to form the enciphered message; which finally was transmitted in morse code.
Every day the German military transmitted many coded messages that went from orders signed by Adolf Hitler, reports with very specific details prepared by some generals at the front line, to weather reports and supply inventories.
This machine gave a great advantage to the Third Reich at that time, mainly because although its way of working was understood, decoding the codes was almost impossible.
The Germans changed the encryption system daily at midnight, and when the British intercepted the message Turing and his team had to work against the clock to develop a system capable of decrypting the messages sent by the Germans before each midnight.
Mathematical geniuses and chess to the rescue
At the age of 26, Alan Turing who had always excelled in mathematics and logic and a master in crossword puzzles joined the Official British Cipher Service.
In 1939 he was a Cambridge teacher and that same year he was recruited by his country’s secret service for a better understanding of Enigma. He and his friend, Gordon Welchman, also a mathematician created ‘Bombe’, a machine that would be able to understand the way of working of Enigma, searching possible correct settings used for an Enigma message.
‘Bombe’ eliminated a large number of probable riddle keys by minimizing the possibilities and it was able to detect when a contradiction existed, therefore discarding such combination.
Initially all Bombe’s devices were operated by ex-military men, but in March 1941 the first detachment of members of the Women’s Royal Naval Service arrived at Bletchley Park to become Bombe operators. By 1945 there were 2,000 women operating the machines.
In 1942 about 40,000 messages were intercepted and decoded which doubled in a month finally managing to intercept and decode two messages per minute.
According to Winston Churchill, the work done by Turing and in support of their scientists and mathematicians shortened the war from two to four years and saved approximately 14 million lives.