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So how were the late Alan Turing (whose 100th birthday is being celebrated in academic circles this June) and his fellow Bletchley Park code-breakers able to crack the Enigma and provide the Allies with such priceless intelligence?

To begin with, Google Internet evangelist Vint Cerf says, there was a lot more to it than raw computational genius.

"It's not entirely a result of the hardware. It's also people making extraordinary guesses about what might have been encoded, the formats, date and time of transmission; all these other things factored into the tactics for trying to break a particular message," he says.