Never have I been so fascinated by a book. This author the art to explain clearly and simply while remaining accurate (it leaves no side retail point). No sooner had I a question that head in following paragraph I had a reply to my question. This book is a novel that explains the history of cryptography since the time of the pharaohs to the present. At the end of the book there are 10 cryptographic tests at progressive levels. I am sad to have finished the book, it is thanks to this that I developed a passion for cryptography at present is to say the masterpiece Simon Singh wrote.