Disappearing Cryptography: Information Hiding: Steganography and Watermarking

By Peter Wayner

Book Overview

Cryptology is the practice of hiding digital information by means of various obfuscatory and steganographic techniques. The application of said techniques facilitates message confidentiality and sender/receiver identity authentication, and helps to ensure the integrity and security of computer passwords, ATM card information, digital signatures, DVD and HDDVD content, and electronic commerce. Cryptography is also central to digital rights management (DRM), a group of techniques for technologically controlling the use of copyrighted material that is being widely implemented and deployed at the behest of corporations that own and create revenue from the hundreds of thousands of mini-transactions that take place daily on programs like iTunes. This new edition of our best-selling book on cryptography and information hiding delineates a number of different methods to hide information in all types of digital media files. These methods include encryption, compression, data embedding and watermarking, data mimicry, and scrambling. During the last 5 years, the continued advancement and exponential increase of computer processing power have enhanced the efficacy and scope of electronic espionage and content appropriation. Therefore, this edition has amended and expanded outdated sections in accordance with new dangers, and includes 5 completely new chapters that introduce newer more sophisticated and refined cryptographic algorithms and techniques (such as fingerprinting, synchronization, and quantization) capable of withstanding the evolved forms of attack. Each chapter is divided into sections, first providing an introduction and high-level summary for those who wish to understand the concepts without wading through technical explanations, and then presenting concrete examples and greater detail for those who want to write their own programs. This combination of practicality and theory allows programmers and system designers to not only implement tried and true encryption procedures, but also consider probable future developments in their designs, thus fulfilling the need for preemptive caution that is becoming ever more explicit as the transference of digital media escalates.

• Format: Paperback
• Language: English
• ISBN: 0123744792
• ISBN13: 9780123744791
• Release Date: December 2008
• Publisher: Morgan Kaufmann Publishers
• Length: 456 Pages
• Weight: 1.75 lbs.
• Dimensions: 1.0" x 7.5" x 9.1"

Customer Reviews

Accessible introduction to a fascinating topic

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

You know you are a crypto geek when....

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!...

A broad introduction to an important topic

This book is filled with mathematical magic tricks that teach you how to disguise information and make it look like something else. The tricks in this book are simple and provide a good understanding about why even numbers aren't what they seem to be. This is the broadest description of steganography and watermarking around.

A nice treatment of an important technology

Steganography is the science of hiding information in plain sight. That is, making it look like something else. This book goes through a number of different schemes for hiding your messages in digital versions of photographs, songs or text. The science is quite good, although the book is getting a bit old. Perhaps the author will issue an updated version soon.

Think Steganography rather than Cryptography.

This book is about concealing the very existence of your messages where cryptography is about obscuring the content of them alone. The two are not quite the same thing, as you'll find out within.