An unusual Bitcoin transaction has puzzled the passionate online community around the cryptocurrency, with some fanatics suggesting the mystery hints at the return of Bitcoin's elusive founder Satoshi Nakamoto.
A line of computer code in the Bitcoin blockchain appears to be so unusual and rare that followers believe it may have been manipulated by Nakamoto, whose Bitcoin holdings would make him or her a billionaire, but who has never been unmasked.
The blockchain technology behind Bitcoin requires each transaction to be processed by working out a complicated hash, or a line of numbers. However, this particular number appears so difficult to achieve given the randomness of the process that some...