Bitcoin gets described in terms of digital wallets, encryption keys and cryptographic hash functions. All of this wizardry plays a part in the anarchic dark web economy, which sends taxmen and police authorities into a spin. But more disruptive than any of the technicalities is the audacity of the basic bitcoin insight – that there is no reason why computers shouldn’t magic up currency from the ether, since all money is made up anyway. Satoshi Nakamoto’s elegant nine-page paper set out the blueprint in October 2008, with perfect timing. Just a month after Lehman Brothers had tumbled, it proposed a payment system that could do away with the need to trust in financial intermediaries or, in plainer parlance, banks. So out goes a need for money to be backed by gold or government fiat, and out too goes the need for established financial institutions. Currency is left naked for what it always was – anything that commands social agreement as a way of settling bills, even if that anything is not a tangible thing at all. How fitting, then, that Mr Nakamoto is not a real person, but a ghost among machines. The many names mooted as the brains behind the Nakamoto mask have included a Finnish sociologist and two Israeli mathematicians. This week it briefly appeared as if the mystery was definitively unravelled, when – on the strength of tax office transcripts and leaked emails – two magazines pointed the finger at Craig Wright, an Australian academic. Wired, however, did concede that it could equally be that Mr Wright himself was a dedicated hoaxer, and so the intrigue lingers on. And when police arrived at the home of the possible inventor of a currency that isn’t, an overflowing letterbox looked like a sign of a man who wasn’t there.