Even as it has grown into a new type of digital money worth billions of dollars, Bitcoin has always retained an air of mystery. Central to its cachet has been the mythic status of the system’s creator. Its developer went by the name Satoshi Nakamoto, but that is all that Bitcoin’s adopters seemed to know — or wanted to know. After all, Bitcoin was a project dedicated in part to making it easier to avoid the all-seeing gaze of the government and corporate America.