06 April 2012

Dissapearing Cryptography

The problem with cryptography books is that either require a degree in mathematics to understand them, or stay in a series of algorithmic recipes for programmers. Finding a work like this book, who knows how to please both those who seek a solid theoretical basis as those seeking a more practical approach is extremely difficult.

Author has managed to structure a book in layers that allow a progressive approach to the subject without having to delve into the arcane details to complete the work with a clear vision of the foundations of cryptography to hide or steganography .Thus, each chapter begins with an overview of the subject matter going after gradually in mathematics. The reader can skip this part at any time to go to mathematical algorithms describing the possible forms of practical benefit to all this. It is so educational and affordable, that even without prior knowledge of steganography, a reader with some agility in a programming languages can do his own data hiding tools after finishing the book.

It is also quite extensive, playing a wide range of information hiding techniques. For example, it has an extremely interesting chapter on steganography using grammars and tree-structured code so that seemingly innocuous texts contain hidden messages completely different. The example used after an alleged sports broadcasting is very revealing ... Of course, it is also the techniques (most popular), hiding in images and sounds coming well in advanced materials, such as manipulation of the coefficients of the FFT to hide information in image compression format, or different techniques for watermarking resistant to suppression or manipulation. It touchs other topics that may not come under the heading of steganography from the orthodox view, but certainly interesting for anyone studying the subject. This is the anonymity of email services, or browsing through remailers and anonymous networks respectively.

Annexes deserve special mention because in them the author delves into the practical side of book.  In one of them offers a practical example in Java of some of the issues.  In other uses LISP to illustrate the chapter of steganography over grammars.  And in another place an intensive review of steganographic tools available online, as well as to deepen the available literature on the subject. 

In short, a highly recommended book for both experts and cryptography and steganography as for those looking to start in this discipline.