The inspiration for this book came from three unwitting sources.
The first was my father. I thought somewhat optimistically that my original (more academic) book about cryptography would be accessible to an informed general reader. My father’s polite indication that he had only managed to dip in and out of the text was a clear signal that a broader audience would require a very different approach to writing. I believe this book has passed the “Dad test.” The second was Edward Snowden. His 2013 revelations launched a public debate about the use of cryptography, and, during the subsequent analysis, I was struck by the discomfort shown by many journalists and politicians concerning cryptography. The third was the anonymous literary agent who, on the basis of articles I wrote for The Conversation, suggested I write a popular science book about cyber security. Be careful what you wish for!
I am fortunate to have worked with Peter Tallack from The Science Factory, who believed in this project from the outset and introduced me to the world of publishing beyond the academic sphere. Thomas Rid told me that Norton would be an outstanding publisher to work with, and he was right. Many thanks to my editor, Quynh Do, for her constant enthusiasm and support, and to Drew Weitman for shepherding the process along so efficiently. I also owe a great debt to Stephanie Hiebert for doling out the punishment I have administered to countless graduate students by “red-penning” the original manuscript so insightfully.
Crucially, a book needs readers. I am extremely grateful for the feedback I received from Sue Barwick, Nicola Bate, Liqun Chen, Jason Crampton, Anne Craw, Ben Curtis, Maurice Elphick, Steven Galbraith, Wen-Ai Jackson, Angus Henderson, Thalia Laing, Henry Martin, Ian McKinnon, Kenny Paterson, Maura Paterson, and Nick Robinson. I’d particularly like to thank Colleen McKenna for her close scrutiny of my wordcraft, and Fred Piper for the eagle eye he cast over my cryptography. Your joint approval gave me the confidence that the balance between the two might be just about right.
Lastly, my special thanks to Ramon the dachshund for loyally sitting by my side as these words were painfully, slowly ground onto the laptop screen, to Kyla and Finlay for suitably distracting me throughout the process, and to Anita for always loving and believing, despite it all.