For my parents . . . my mentors and heroes A debt of gratitude: to my editors at St. Martin’s Press, Thomas Dunne and the exceptionally talented Melissa Jacobs. To my agents in New York, George Wieser, Olga Wieser, and Jake Elwell. To all those who read and contributed to the manuscript along the way. And especially to my wife, Blythe, for her enthusiasm and patience. Also . . . a quiet thank you to the two faceless ex‑NSA cryptographers who made invaluable contributions via anonymous remailers. Without them this book would not have been written.