But the British signals intelligence agency can now expect a sudden influx of ‘applicants’ after James Firth’s solution was published on the Open Digital Policy Organization website in the early hours of Monday morning. The challenge is, he admits, “fiendishly difficult”; but requires more computer science and software engineering expertise than cryptanalysis capability.

The solution reportedly takes three stages. The first is to locate a hidden URL in the challenge code. The second stage is to write a virtual machine that decrypts the first part and provides a second URL. Stage three is provided by the second URL and contains the keyword target.

Submitting this keyword to GCHQ apparently results in the offer of a £31k job – not, it has to be said, a huge amount for a computer scientist in today’s market.