The concept of Blockchain was made by two people in 1991; Stuart Haber and Scott Stornetta. They published their first white paper. You could call it the first bitcoin white paper. However, it wasn’t accepted until 1997. Until 2009 only the theoretical concept of blockchain existed until bitcoin was made. So the technology running the bitcoin has been around for decades. However, the first ever implementation was in 2009.

As far as it goes for Satoshi Nakamoto, a lot of theories exist. Although no one actually knows the truth. It is very likely for both theories to be true as it could be a single person or a whole team. Single person because all bitcoin is just a piece of software made upon a technology that has been around for over a decade. However, to implement such novel ideas into the practical life would require a lot of brain power for thinking, analysis, devising the plan and so on.