The job ad is being put out by Britain's version of America's National Security Agency.
British citizens who solve the cryptographic puzzle could be recruited as the next generation of high tech spies. The website has received thousands of hits and at least 50 people have solved it.
An official for the British government says the puzzle is not designed to be overly difficult, but it is a good way to promote awareness of the agency and to get young people excited about careers in legitimate cyber-espionage.
