People had been thinking about digital money for decades but didn’t know how to solve double spend. Proof of work was around since 2000 or so (hashcash) but it

People had been thinking about digital money for decades but didn’t know how to solve double spend. Proof of work was around since 2000 or so (hashcash) but it wasn’t until satoshi that these ideas were congealed together in the form of the blockchain.