Peter Wayner - Disappearing Cryptography, Third Edition: Information Hiding: Steganography & Watermarking

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Copyright 2009 by Peter Wayner. Published by Elsevier Inc.

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Library of Congress Cataloging-in-Publication Data

Wayner, Peter, 1964

Disappearing cryptography: Information hiding: Steganography & watermarking / Peter Wayner. 3rd ed.

p. cm.

Includes bibliographical references and index.

ISBN 978-0-12-374479-1 (alk. paper)

1. Computer networksSecurity measures. 2. Cryptography. 3. Internet.

I. Title.

TK5105.59.W39 2009

005.82dc22 2008044800

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Peter Wayner is the author of more than a dozen books, if you include the different versions of this book, Disappearing Cryptography. This book is one of the best examples of a common theme in his work, the idea that information can hide from everyone. (The first edition came with the subtitle Being and Nothingness on the Net, a choice that lost out to the power of keyword searches on the Internet. It's one thing to hide when you want to hide, but not when someone is looking for a book to purchase on Amazon.)

Other books that follow in this theme are:

• Digital Cash, An exploration of how to move money across the Internet by creating bits that can't be counterfeited. [Way95b]
• Translucent DatabasesA manifesto on how to preserve privacy and increase security by creating databases that do useful work without having anything in them. [Way03]
• Digital Copyright ProtectionHow to keep content on a flexible leash. [Way97b]
• Policing Online Games How to enforce contracts and keep games honest and fair. [Way05]

He writes often on technical topics for venues like New York Times, InfoWorld, Byte, Wired and, on occasion, even a USENET newsgroup or two.

When he's not writing, he consults on these topics for a wide range of companies.

This book is a third edition and so that means more thanks for everyone. There is no doubt that I owe a debt of gratitude to the participants in the cypherpunks and coderpunks mailing lists. Their original contributions inspired me to write the first book and their continual curiosity makes it one of the best sources of information around.

Some newer mailing lists are more focused on the topic. The watermarking list and the stegano list both offer high quality discussions with a high signal-to-noise ratio. Other lists like the RISKS digest and Dave Farber's Interest People list helped contribute in unexpected ways. Of course, modern list-like web sites like Slashdot, Kuro5hin, and InfoAnarchy contributed by offering solid, moderated discussions that help the signal jump out of the noise. It is impossible to thank by name all of the members of the community who include plenty of solid information and deep thought in their high-quality postings.

The organizers of the Information Hiding Workshops brought some academic rigor to the area by sponsoring excellent workshops on the topic. The discipline of creating, editing, reviewing, presenting and publishing a manuscript advanced the state of the art in numerous ways. The collected papers published by Springer-Verlag are a great resource for anyone interested in the development of the field.

Some others have helped in other ways. Peter Neumann scanned the first manuscript and offered many good suggestions for improving it. Bruce Schneier was kind enough to give me an electronic version of the bibliography from his first book [Sch94]. I converted it into Bibtex format and used it for some of the references here. Ross Anderson's annotated bibliography on Information Hiding was also a great help.

Scott Craver, Frank Hartung, Deepa Kundur, Mike Sway, and three anonymous reviewers checked the second edition. Their comments helped fixed numerous errors and also provided many suggestions for improving the book.

The original book was originally published by AP Professional, a division of Harcourt-Brace that blended into Morgan Kaufmann. The team responsible for producing the first edition was: Chuck Glaser, Jeff Pepper, Mike Williams, Barbara Northcott, Don DeLand, Tom Ryan, Josh Mills, Gael Tannenbaum, and Dave Hannon.

The second edition would not exist without the vision and support of Tim Cox at Morgan Kaufmann. I would like to thank Tim and Stacie Pierce for all of their help and encouragement.

The third edition exists because Rick Adams, Gregory Chalson and Denise Penrose saw the value in the book and devoted their hard work and energy to bringing it to market again. Sherri Davidoff, Rakan El-Khalil, Philipp Ghring, Scott Guthery, J. Wren Hunt, John Marsh, Chris Peikert Leonard Popyack and Ray Wagner read portions of the book and provided invaluable help fixing the book.

October 2008

http://www.wayner.org

. The periods and commas are left outside of all quotes to prevent confusion.

Hyphens also cause problems when they're used for different tasks. LISP programmers often use hyphens to join words together into a single name like this: Do-Not-Call-This-Procedure. Unfortunately, this causes grief when these longer words occur at the end of a line. In these cases, there will be an extra hyphen included to specify that there was an original hyphen in the word. This isn't hyper-compatible with the standard rules that don't include the extra hyphen. But these rules are for readers who know that self-help is a word that should be hyphenated. No one knows what to think about A-Much-Too-Long-Procedure-That-Should--Be-Shortened-For-Everyone.

This book is about making information disappear. For some people, this topic is a parlor trick, an amazing intellectual exercise that rattles around about the foundations of knowledge. For others, the topic has immense practical importance. An enemy can only control your message if they can find it. If you hide data, you can protect your thoughts from censorship and discovery.

The book describes a number of different techniques that people can use to hide information. The sound files and images that float about the network today are great locations filled with possibilities. Large messages can be hidden in the noise of these images or sound files where no one can expect to find them. About one eighth of an image file can be used to hide information without any significant change in the quality of the image.

to turn data into something entirely innocent like the voice-over to a baseball game. Bad poetry is even easier to create.

show how a group of people can communicate without revealing who is talking. Completely anonymous conversations can let people speak their mind without endangering their lives.