Despite its enormous profile, no-one actually knows for sure who invented Bitcoin. The idea for it was posted on internet forums in 2008 by someone calling themselves Satoshi Nakamoto.
They explained how a peer-to-peer digital cash system could work to enable people to send virtual coins over the internet, just as easily as sending an email.
Satoshi created a complex computer system that would process transactions and create new coins using a huge network of self-appointed volunteers around the world who used special software and powerful computers.
But he – or they – never revealed their identity, and the world has never worked it out.
In 2014, Japanese-American man Dorian Nakamoto was pursued by reporters who thought he was the elusive Bitcoin creator, but it proved to be a false lead caused by some mistranslated information.
Australian computer scientist Craig Wright said it was him in 2016 – but after years of legal battles, a High Court judge concluded he was not Satoshi.
Earlier this year, a Canadian Bitcoin expert called Peter Todd strongly denied being Satoshi, while in London this month a British man, Stephen Mollah, claimed he was – but no-one believed him.
