Before continuing, for those of you intending to complete the Cipher Challenge for yourself, I must warn you that this page contains spoilers! If you want to know more about the background to the Cipher Challenge then you can start by reading the rest of this introductory page, or you will find articles about the Challenge in The Telegraph, The Hindu, you will find out how it was cracked, and an archive of material published during the competition. Although the solutions are now public knowledge, you might want to exercise your brain and crack a few of them. You can also find the actual ciphertexts on-line. This section also contains the final leaderboard, which shows who cracked what, and a small gallery of photos that relate to the cipher challenge. It also contains essays by Jim Gillogly and John Palagyi, who might be considered as runners-up, and a highly readable 40-page report by the Swedish team who solved the Challenge (see below). This part of the website attempts to tell the story behind the Cipher Challenge. The Challenge was officially solved on October 7, 2000, after one year and one month of arduous effort by codebreakers, amateur and professional, around the world.

In addition to the intellectual reward of cracking all ten messages, there was a prize of £10,000 for the first person to solve the Challenge. The Cipher Challenge was a set of ten encrypted messages to be found at the end of The Code Book, a history of codes and code breaking that I published last year.

The Code Book by Simon Singh