Science & Technology

Alan Turing, Who Cracked Nazi Code, Gets Posthumous Pardon

By Scott Neuman

Published December 23, 2013 at 7:52 PM CST

Detail of a Turing Bombe machine in Bletchley Park Museum in Bletchley, central England. The device, the brainchild of Alan Turning, was instrumental in cracking the German code during World War II.

British mathematician Alan Turing, who helped crack Nazi Germany's 'Enigma' code and laid the groundwork for modern computing, was pardoned on Tuesday, six decades after his conviction for homosexuality is said to have driven him to suicide.

Following his singular contributions toward winning the war against Adolph Hitler, Turing's 1952 conviction is believed to have led two and a half years later to him taking his life by ingesting cyanide.

The Associated Press reports:

"Turing made no secret of his sexuality, and being gay could easily lead to prosecution in post-war Britain. In 1952, Turing was convicted of "gross indecency" over his relationship with another man, and he was stripped of his security clearance, subjected to monitoring by British authorities, and forced to take estrogen to neutralize his sex drive - a process described by some as chemical castration."

A four-rotor Enigma machine, right, once used by the crews of German U-boats in World War II to send coded messages. Turing helped crack the sophisticated code.

On Tuesday, Queen Elizabeth II issued the belated pardon. Justice Secretary Chris Grayling said in a prepared statement that Turing's treatment was unjust and that the legendary code breaker and computer theorist "deserves to be remembered and recognized for his fantastic contribution to the war effort and his legacy to science."

Britain's , the secret code-breaking headquarters, used electro-mechanical machines dreamed up by the mathematician and known as " Turing bombes" to identify the correct settings to decode messages produced on Germany's 'Enigma' ciphering machines.

In a series of scientific papers before and after the war, Turing laid out what many consider the foundations of modern computing. One paper, dating from 1946 detailed a "stored-program computer" and two years later, he produced a treatise entitled Intelligent Machinery that remained unpublished until after his death.

It wasn't until last year that some of those papers were finally declassified and released by the British government.

Among Turing's more far-sighted ideas was the so-called Turing Test of a machine's ability to exhibit intelligent behavior.