Disappearing Cryptography, Second Edition - Information Hiding: Steganography and Watermarking (The Morgan Kaufmann Series in Software Engineering and Programming)
By Peter Wayner
* Publisher: Morgan Kaufmann
* Number Of Pages: 413
* Publication Date: 2002-04-29
* ISBN-10 / ASIN: 1558607692
* ISBN-13 / EAN: 9781558607699
* Binding: Paperback
Product Description:
Disappearing Cryptography, Second Edition describes how to take words, sounds, or images and hide them in digital data so they look like other words, sounds, or images. When used properly, this powerful technique makes it almost impossible to trace the author and the recipient of a message. Conversations can be submerged in the flow of information through the Internet so that no one can know if a conversation exists at all.
This full revision of the best-selling first edition describes a number of different techniques to hide information. These include encryption, making data incomprehensible; steganography, embedding information into video, audio, or graphics files; watermarking, hiding data in the noise of image or sound files; mimicry, "dressing up" data and making it appear to be other data, and more. The second edition also includes an expanded discussion on hiding information with spread-spectrum algorithms, shuffling tricks, and synthetic worlds. Each chapter is divided into sections, first providing an introduction and high-level summary for those who want to understand the concepts without wading through technical explanations, and then presenting greater detail for those who want to write their own programs. To encourage exploration, the author's Web site www.wayner.org/books/discrypt2/ contains implementations for hiding information in lists, sentences, and images.
Each chapter is divided into sections, providing first an introduction and high-level summary for those who want to understand the concepts without wading through technical details, and then an introductory set of details, for those who want to write their own programs. Fully revised and expanded. Covers key concepts for non-technical readers. Goes into technical details for those wanting to create their own programs and implement algorithms. Up-to-date website containing the code samples from the book.
Summary: Accessible introduction to a fascinating topic
Rating: 5
This is a very easy read that does not really assume much about the reader other than mathematical maturity at the precalculus level, knowledge of programming in a higher level language, and a curiosity about hiding information in such things as images. In fact, I bought this book to get a grasp on how to hide a watermark in an image. The early chapters are devoted to material that forms the basic toolkit for steganography - private key encryption, secret sharing, and error correcting codes. The later chapters describe how to apply these techniques in various ways to hide information.
Chapter 5 discusses common data compression algorithms, not to the point that you could write an encoder/decoder system, but so that you know which allow perfect reconstruction and which do not. Compression leads to the topic of mimicry, which is the subject of chapter 6. Basic mimicry produces text that looks statistically similar to the original text but is far from perfect. Chapter 7 shows methods of improving mimicry techniques so that the mimicked text not only passes statistical tests for similarity to the original, but passes rules for grammar. This leads to the concept of context free grammars and their role in mimicry. Thus, you can hide data in realistic sounding text.
Chapter 8 concentrates on a robust and complete model known as the Turing machine. Such a machine hides data as it "runs forward", while running the machine in reverse allows the hidden data to be recovered. Certain proofs show that this is a stronger data hiding model than those previously discussed.
Chapter nine discusses a more image-processing related data hiding topic - hiding in the noise. What appears as noise to the untrained eye can actually be a message. Of course, the flip side of this is "real" noise has the power to obscure the hidden message.
Chapter 10 discusses anonymous remailers, which is the deletion of the name of the originator of a message by an intermediate node. Such systems can range from very secure to very insecure depending on strategies involved. Chapter 11,"Secret Broadcasts", is a companion chapter on how to broadcast a message so that everyone can read it but nobody knows the source. The solution lies in the "Dining Cryptographers" algorithm, and this solution is discussed at length.
Chapter 12, "Keys", discusses message keys as extensions to the concept of keys in basic cryptography, which was discussed earlier in the book. Adding keys to any algorithm discussed up to this point makes that algorithm stronger. Chapter 13, "Ordering and Reordering", discusses how steganography strategies might be disrupted by reordering parts of a message, and discusses methods that might prevent this from being a problem.
Chapter 14, "Spreading", is a more mathematical chapter than the preceding ones and takes a different approach to the problem of information hiding. It takes ideas from spread spectrum radio and applies them to steganography. This is the one chapter where a knowledge of calculus, Fourier transforms, and even wavelets will be helpful.
The last three chapters, "Synthetic Worlds", "Watermarks", and "Steganalysis" are short and more subjective than previous ones, mainly giving the reader a broad overview of these topics.
The book has a wealth of algorithms, equations, and simple examples. There is even a very basic Java mimicry program in the appendix. However, this is not a programming book full of ready to implement solutions - you will have to do that yourself. There are numerous references to web addresses where you can find both executable and source code for implementing some of the algorithms mentioned in this book. I would say if you are interested in hiding information in data of any kind - text, sound, imagery, etc. - then this book is essential reading. I highly recommend it.
Summary: One year after purchase, I keep opening this book
Rating: 5
All in all just a fascinating book on a fascinating topic. In general, the introductory parts of each chapter are accessible to anyone with a standard 12 year education. The mathematics are best understood by people with a background in algebra and statistics at the American High School level, but not much more. If you buy this book, expect John Ashcroft to put your name on a list of people buying dangerous published works (and with the Patriot Act in place, I am neither paranoid nor joking). The best chapter is the one about encoding information in ordered lists. This book taught me how to include a one line hidden message in a 50 item list of my favorite Country and Western Songs of all time (and THAT is a cool thing to do).
Summary: Excelent book
Rating: 5
I read the entire book from first to last page and enjoyed the content absolutely. The book has theory and practice, clear examples and many references to free and open source software to make tests. The math part has razonable level (not too much, not to little). I have no found anything better in the area.
Good for Peter Wayner!
P.D. ...
Summary: You know you are a crypto geek when....
Rating: 5
This book is a great introduction to learning how to hide data in places most people wouldn't think about looking. Sample code and various URL's are provided for places to start, this not the easiest subject to grasp, but the book helps put it at a manageable level.
A great place to start!...
Summary: Cool, deep, although a bit goofy
Rating: 5
This is a deep, serious book about making information transmogrify, even if there are a few silly parts. I liked the funny parts and they reminded me of Goedel Escher and Bach
http://ifile.it/8s1bxv4/1558607692.rar
