Hal Finney was a computer scientist known for being an early contributor to Bitcoin’s development. Finney received the very first Bitcoin transaction from Satoshi Nakamoto himself. Finney’s interest in cryptography existed long before Bitcoin and he is credited with creating the first reusable proof-of-work system years prior, in 2004.
Much speculation exists that Finney was in fact Satoshi Nakamoto himself despite Finney denying these claims. Finney sadly passed away in 2014 after a battle with ALS.