The origins of bitcoin trace back to 2008, when its creator, who went by the pseudonym Satoshi Nakamoto, published a proof of concept for Bitcoin. The proof was then published to a cryptocurrency mailing list in 2009. Nakamoto left the project in 2010 and disappeared, but other developers picked up the work. Bitcoin’s birthday is Jan. 3, when Nakamoto mined the first 50 units of the currency.