Hal Finney was a software engineer and cryptography activist. He was the first identified bitcoin developer after Satoshi Nakamoto, and the recipient of the first bitcoin transaction.
Hal Finney was an early bitcoin pioneer. He was the first identified bitcoin developer after Satoshi Nakamoto, and in January 2009, he became the recipient of the first bitcoin transaction. Finney was one of the people rumoured to be behind the Satoshi pseudonym.
A software engineer and noted name in cryptography, Finney developed the first proof-of-work based digital cash system, RPOW (Reusable Proofs of Work), which was based on Adam Back's Hashcash. Created with an aim to implementing it in a digital currency system, RPOW was a precursor to bitcoin.
Finney was the second developer to work on the PGP software system after founder Phil Zimmermann, and he continued to work for PGP Corporation until his retirement in 2011. He was also a vocal cryptography activist and an early member of the Cypherpunks.
Finney was diagnosed with ALS in 2009 and was wheelchair-bound for the last few years of his life. He died in 2014 at the age of 58.