For centuries, nations around the world have operated Black Chambers, secret rooms where they attempted to decode the messages being sent by their rivals. The French operated the Cabinet Noir, in Vienna the Geheime Kabinets-Kanzlei was the home of Austria's greatest codebreakers, and in Britain there was Room 40 and then Bletchley Park.
This is Simon Singh's virtual Black Chamber, where you can learn about codes and codebreaking, encrypt your own messages, crack those of your enemies, and play with interactive enciphering programmes.
The Black Chamber provides a brief history of cryptography from Ancient Rome to today's Information Age, and it is also a mini-tutorial in codes and codebreaking. If you want to know more, then a not-for-profit CD-ROM containing all the material in this website and lots more is available. It contains more sophisticated material (e.g., an Enigma emulator), advanced tools (RSA encryption), items that would not work over the Internet (animations of quantum cryptography), and notes for teachers.
The CD-ROM also has video clips from Simon's TV series, The Science of Secrecy. The clips include Simon Singh demonstrating an Enigma machine, the world's oldest document on codebreaking filmed in Istanbul, interviews with Whit Diffie and Len Adleman, and the first recording of an interview with a GCHQ cryptographer.