Olivier Langlois's blog

This book is extremely complete. It briefly covers the history of cryptography. It describes the political implications of cryptography and finally it shows how cryptography can be used in applications and presents the different cryptographic algorithms.

The algorithm section starts with a number theory primer.Honestly, I have found it a little bit too thin to learn all the needed background to fully understand the algorithms but on the other side, you cannot expect a simple 600 pages book to provide that background in the latest mathematical research number theories. It has at least the merit that it did stimulate my curiosity about number theory when I have read the first edition of this book.

Another point that makes this book interesting is that at the end of each chapter presenting the various algorithms in a given category, you will get Bruce Schneier opinion on which algorithm is the best. Of course, this type of information usually become outdated real fast but it is interesting to follow his thought process and test his predictions as the book grow older.

So, if you are looking for your first cryptography book, it should be this one.