When I wrote my first book, Fermat’s Last Theorem, I made a passing reference to the mathematics of cryptography. Although I did not know it at the time, this was the start of a major interest in the history and science of codes and code breaking, which has resulted in a 400-page book on the subject, an adaptation of the book for teenagers, a 5-part TV series, numerous talks and lectures, the purchase of an Enigma cipher machine and the development of an interactive crypto CD-ROM.
You can find information about TV series and the free CD-ROM version of the book (and lots more) in the Cryptography section of the site. In this section, however, you will find details about my book on cryptography (The Code Book).
I have not included any material about the teenage version of The Code Book, but you can find it at Amazon.co.uk and Amazon.com.