The Code Book: The Secret History of Codes and Code-breaking

by Simon Singh

When the codebreakers have developed a new weapon that reveals a code’s weakness, then the code is no longer useful. It either becomes extinct or it evolves into a new, stronger code. In turn, this new code thrives only until the codebreakers identify its weakness, and so on. This is analogous to the situation facing, for example, a strain of infectious bacteria. The bacteria live, thrive and survive until doctors discover an antibiotic that exposes a weakness in the bacteria and kills them. The bacteria are forced to evolve and outwit the antibiotic, and, if successful, they will thrive once again and re-establish themselves. The bacteria are continually forced to evolve in order to survive the onslaught of new antibiotics.

Alan Turing was another cryptanalyst who did not live long enough to receive any public recognition. Instead of being acclaimed a hero, he was persecuted for his homosexuality. In 1952, while reporting a burglary to the police, he naively revealed that he was having a homosexual relationship. The police felt they had no option but to arrest and charge him with ‘Gross Indecency contrary to Section 11 of the Criminal Law Amendment Act 1885’. The newspapers reported the subsequent trial and conviction, and Turing was publicly humiliated. Turing’s secret had been exposed, and his sexuality was now public knowledge. The British Government withdrew his security clearance. He was forbidden to work on research projects relating to the development of the computer. He was forced to consult a psychiatrist and had to undergo hormone treatment, which made him impotent and obese. Over the next two years he became severely depressed, and on 7 June 1954, he went to his bedroom, carrying with him a jar of cyanide solution and an apple. Twenty years earlier he had chanted the rhyme of the Wicked Witch: ‘Dip the apple in the brew, Let the sleeping death seep through’. Now he was ready to obey her incantation. He dipped the apple in the cyanide and took several bites. At the age of just forty-two, one of the true geniuses of cryptanalysis committed suicide.