National Cipher Challenge

The competition will run from October 1st 2009 to January 2nd 2010. Over the next few months you will be joining Ada Lovelace and Charles Babbage as they endeavour to save the world’s first computing engines, the Difference Engine and the Analytic Engine from falling into the hands of arch criminials and enemies of the British Empire. You will also need to help them break the Byron Enigma.

Source: here