^{( FEB 23, 2024; https://bitcoinmagazine.com/ )}

More Satoshi Nakamoto track

As detailed, the correspondence between the two was polite and professional, with Back pointing Satoshi to a few related papers, and Satoshi seeking to make clear the unique contributions he added to Back's prior work.

Invented in the 1990s by Back, Hashcash was a method for slowing email spam, one that prompted a computer's processor to prove it had conducted calculations before delivering the message. The system is the blueprint for Bitcoin's mining system, in which a distributed network of computers compete to solve cryptographic puzzles, and in exchange for the work, release new bitcoins into the economy.

Souce