This book is all the better for its reviewers, including Seth Arnold, Theo de Raadt, Erik Fichtner, Bob Fleck, Simson Garfinkel, Russ Housley, Mike Howard, Douglas Kilpatrick, Tadayoshi Kohno, John Regehr, Ray Schneider, Alan Schwartz, Fred Tarabay, Rodney Thayer, David Wagner, Scott Walters, and Robert Zigweid. In addition, we would like to single out Tom O'Connor for his Herculean efforts in review and detailed comments.

Zakk Girouard did a lot of background work for us on material in Chapter 1, Chapter 2, Chapter 3, and Chapter 8, and wrote some text for us. We're very grateful, and, dude, we're sorry we didn't make it to your winter solstice party; we tried!

We'd also like to thank the wonderful staff at O'Reilly, particularly our editor, Debby Russell. They were all extraordinarily accommodating, and it was a pleasure working with them. In fact, this project was originally O'Reilly's idea. Sue Miller, our first editor at O'Reilly, initially suggested a Cryptography Cookbook that we were happy to do, and it evolved from there. Thanks for tapping us to write it. Thanks as well to Jon Orwant, who helped in the initial stages of the project.

Many thanks to Gene Spafford for contributing a wonderful foreword to this book and for his many contributions to the field.

Matt Mackall lent us his expertise, helping us to write Recipe 11.19 and providing good feedback on the rest of Chapter 11.

Chapter 12 was written "on the clock," by Secure Software staff, thanks to a contract from the Air Force Research Labs. Martin Stytz and Dawn Ross were responsible for the contract on the Air Force side, and they were a pleasure to work with. Eric Fedel, Zachary Girouard, and Paolo Soto were part of the technical work on this effort, and Kaye Kirsch provided (fantastic) administrative support.

Thanks to everyone at Secure Software for supporting this book, including Admiral Guy Curtis, Kaye Kirsch, and Peter Thimmesch. In addition, we'd like to thank Bill Coleman for being an all-around cool guy, even though he 12:10'd much of our caffeine supply and our stash of late-night snacks.

Finally, we'd like to thank Strong Bad for teaching us how to type up a book while wearing boxing gloves.

John Viega: Thanks to Crispin Cowan, Jeremy Epstein, Eric Fedel, Bob Fleck, Larry Hiller, Russ Housley, Tetsu Iwata, Tadayoshi Kohno, Ben Laurie, David McGrew, Rodney Thayer, David Wagner, Doug Whiting, and Jason Wright for conversations that ended up improving this book, either directly or indirectly. Thanks also to my good friend Paul Wouters for hosting the book's web site. And, as always, thanks to my family for their unflagging support. My daughters Emily and Molly deserve special thanks, because time I spend writing is often time I don't get to spend with them. Of course, if they were given a choice in the matter, this book probably wouldn't exist....

Over the years I've been lucky to have a number of excellent mentors. Thanks to Matt Conway, Russ Housley, Gary McGraw, Paul Reynolds, Greg Stein, and Peter Thimmesch?you were/are all excellent at the role.

I'd also like to thank Matt Messier for the awesome job he did on the book. I'm sorry it was so much more work than it was intended to be!

Finally, I would like to thank sugar-free Red Bull and Diet Dr. Pepper for keeping me awake to write. Narcolepsy is a pain.

Matt Messier: I would like to thank Jim Archer, Mike Bilow, Eric Fedel, Bob Fleck, Brian Gannon, Larry Hiller, Fred Tarabay, Steve Wells, and the Rabble Babble Crew (Ellen, Brad, Gina, and Michael especially) for moral support, and for listening to me ramble about whatever I happened to be writing about at the time, regardless of how much or how little sense I was making. An extra special "thank you" to my parents, without whom I would never be writing these words.

Thanks also to John Viega for pulling me in to work on this book, and for consistently pushing to make it as great as I believe it is. John, it's been a pleasure working with you.

Finally, a big thanks goes out to Red Bull and to Peter's wonderful contribution of the espresso machine in the kitchen that got me going every morning.