Adam Back Recalls Contributions of Hal Finney to Blockchain Technology


August 29, 2020 9:32 am

Adam Back Recalls Contributions of Hal Finney to Blockchain Technology
3856 Total Views

In the earliest days of Bitcoin, Hal Finney is known as an early supporter of Bitcoin (BTC). Without being overtly sceptical about its prospects, Finney was the only one who fully understood the possibilities of the technology. 

Finney was also one of the first people to respond to Satoshi Nakamoto’s initial post on the cypherpunk mailing list. It’s been six years since Hal Finney passed away from the Amyotrophic Lateral Sclerosis (ALS). Cryptographer Adam Back recalls Hal Finney as a constructive personality who never engaged in squabbles.

Hal Finney was a developer for PGP Corporation, which owned Pretty Good Privacy software or PGP. The software allowed users to encrypt their texts, emails and files and was the second developer hired after Phil Zimmermann. He was one of the well-known cryptographers in the cypherpunk community even before his involvement with Bitcoin. 

In 2004, Finney developed Reusable Proofs of Work software or RPOW. It built on the proof-of-work concept developed by Adam Back in Hashcash by introducing reusability, hence the name. This was one of the stepping stones to Bitcoin; interestingly though, Satoshi did not cite Finney’s work in his white paper.

Finney was the first person outside of Satoshi to start mining Bitcoin, he was also the recipient of the first transaction. In 2009, he was diagnosed with ALS. At first, the disease progression was slow, but last months of his life, Finney spent completely paralyzed. Before his death, Finney and his wife Fran worked to raise awareness and fundraising for ALS. After he died in 2014, Finney’s body was cryopreserved. Since his departure, Fran Finney has continued her husband’s legacy. 

Adam Back stated that he had some email exchanges with Finney over the years, including a request for Back to comment on RPOW. Though they never met in person, Back recollects Finney fondly:

Well, I never met him in person, but I consider him to be a constructive personality more interested in building things than arguing about politics. While building things with cypherpunk intent, he would just focus on the constructive part of conversations. Don’t think I ever saw him participate in online arguments on the cypherpunks list.

In his farewell post on, he shared his journey about the last four years, titled as “an eventful time for Bitcoin and me,” in which he introduced himself to the people, who don’t know him, described his journey from where he started, opportunities he got and his involvement in Bitcoin and when he diagnosed with a fatal disease, his struggle with it. He considered himself lucky in his last lines to have a satisfying life. 

No Comments