Gordon Corera - Cyberspies: The Secret History of Surveillance, Hacking, and Digital Espionage

This book has grown out of reporting on issues related to intelligence and cyber security over a number of years. It based in part on interviews with many individuals who have worked in the field and I am grateful for their assistance. Endnotes indicate where people have spoken on the record but there are many others who have provided advice and thoughts who would likely not thank me for naming them here. But they too have my gratitude.

I am particularly indebted to those who read drafts of parts of the book and provided comments. Other people and institutions I would like thank for help in my research include: the National Museum of Computing, the National Cryptologic Museum and its librarian Ren Stein, Bletchley Park, the Imperial War Museum and its sound library, the National Archives at Kew, the Charles Babbage Institute at the University of Minnesota, Satu Haase-Webb for research assistance in the US National Archives, Charlotte Dando at the Porthcurno Telegraph Museum, David Hay at the BT Archive, Erich Schmidt-Eenboom in Germany and my colleagues at the BBC, especially Mark Savage. My agent Georgina Capel has provided support and encouragement, while this book would not be what it is without the guidance and patience of my editor Bea Hemming. My greatest debt is owed to my family.

By the Second World War, Tommy Flowers, the boy who had stood in his East End garden and watched a Zeppelin brought down in a flaming mass during the First World War, had graduated from Meccano sets and toy engines to building his own machines. In his laboratory at Dollis Hill in late 1943 he was going to test the limits of his new creation. He switched it on and a whirring gathered pace with a click as the telegraph tape turned a cycle every few seconds. The delay between the clicks shortened as the pace quickened. Twenty miles an hour. Thirty. Flowers kept pushing. The tape was now a blur of white. Forty. Fifty. The pulley wheel was spinning the tape around something known as the bedstead because it looked like an upright bed frame. Finally the tension was too much. The paper tape, travelling through the machine at 10,000 characters every second, suddenly snapped in several places. Scraps of paper exploded into the air, shreds falling all around the laboratory like snowflakes amid the noise. It was really just pandemonium, Flowers recalled. Sixty miles an hour, he now knew, was the absolute limit, so a safe speed would be half that. The paper pandemonium meant his machine was nearly ready. Flowers was building something that would change the war and the world. The ambition was reflected in its name Colossus.

The suburb of Dollis Hill was home to a large, bureaucratic-looking brick building that housed the Post Office research laboratory. The words Research is the Door to Tomorrow were inscribed in stone above the entrance. When the air-raid sirens went off, one of Flowers assistants, the mildly eccentric Doc Coombs, would grab his tin hat and race up to the roof and shout Bandits at 12 oclock!, fearing incendiary bombs might destroy their work. The destination was Bletchley Park.

Flowers had been born in Londons East End in 1905, a boy who was good with numbers but struggled with words.favourite tea mug to the radiator. But Flowers first impression of the younger man with his straight dark hair was that he seemed quite normal except for a pronounced stammer. He explained the technology of code-breaking, Flowers said of that first meeting. He was concerned with the Enigma.

These two central figures in the advent of the computer age, neither of whose contributions were appreciated during their lifetimes, could not have been more different. One had followed the path of public school to becoming a fellow of Kings College, Cambridge, the other was a working-class East End boy who had been to night school. But despite their different paths, they had been brought together because they had proved to be brilliant innovators in the years leading up to the war, reaching the elite institutions within their own respective fields. Those two areas of expertise maths and engineering would then fuse in the white heat of war to forge something new. Bletchleys success was built on the way it threw such different people together.

Turings wartime work focused on breaking Enigma, but his wider effort before and after the war laid the foundations for modern computing. As a schoolboy aged seventeen, Alan Turing had first encountered the world of codes and ciphers thanks to a maths book he had chosen as a school prize. The book remarked on the romance and challenge in discovering a secret key to a message and Turing was one of those captivated. The prize also had a deeply personal meaning to Turing. It had been endowed in the name of a boy from the year above with whom Turing had fallen in love but who then died. Tragedy drove Turing deeper into science as if in tribute, taking him to Cambridge and advanced mathematical thinking. By 1935, the twenty-three-year-old Alan Turing was wrestling with what seemed an abstract question. Was all mathematics decidable? In other words, could its methods be applied to any assertion to prove whether it was true or not? Turings mentor at Cambridge, Max Newman, had posed the question in a different way: was there a mechanical process which could be applied to a mathematical statement to see if it could be proved? After a long run out of town by the river to the village of Grantchester, Turing lay in a meadow in the early summer of 1935 and pondered what such

The next year, while working on his Ph.D. at Princeton, Turing finished an academic paper that, then obscure, would eventually be seen as a pivotal work of the twentieth century. On Computable Numbers is thirty-six pages long and aimed to answer a theoretical question. Much of it is filled with dense mathematical symbols and equations. And yet within it are ideas whose clarity and importance stand out even to the modern, lay reader. The term computer was not new: previously it had applied to people. They might be performing some calculation, such as Kathleen Lewis working on the correct trajectory to launch an artillery shell to hit a moving target. Or carrying out a repetitive action, a bit like the hundreds of poor examiners who sat opening and reading messages in the First World War. They had to follow strict rules, with the idea of making the process of deciding whether a letter or telegram could be passed to go on its way or stopped for further reading as mechanical or automated as possible. For instance, when scanning a telegram, was one of the names or addresses on a blacklist present or not? A simple yes/no question was needed in order to maximise efficiency when dealing with such a large volume. These kinds of people-computers, Turing said, would have a set of instructions what he called a state of mind; they would then apply this to the symbols or the data placed before them. The behaviour of the computer at any moment is determined by the symbols which he is observing, and his state of mind at that moment, Turing wrote. But if this process of performing instructions was broken down into the simplest possible components, could a machine undertake it? Turing imagined a machine that scanned two paper tapes, one feeding in instructions and another feeding in data on which the instructions would compute. Even the most complex calculation, he thought, could be reduced to its simplest form an elementary operation in which the state of a symbol was either altered or stayed the same. Before reverting back to pages of equations, Turing writes a simple sentence: We may now construct a machine to do the work of this computer.

Until Turings insight, machines were designed to fulfil a particular

Turings idea was academic abstraction in 1936. Charles Babbage and Ada Lovelace had conceived of mechanical computing machines a century earlier, and others in America were nearing the same conclusions in the 1930s. But Turings concept, involving symbols, logic and instructions, also coincided with the arrival of electronics and war would turn his ideas into something tangible. The day after he sat in his Cambridge rooms and heard Neville Chamberlain on the radio announcing war had been declared with Germany, Turing reported for duty at Bletchley Park. He had been recruited to use his remarkable mind on the challenge that was stumping British code-breakers, the same challenge that Turing had told Flowers about at their meeting. It was Enigma what many thought was an unbreakable code.