Samson Mow, the CEO at JAN3 and the former CSO at Adam Back’s Blockstream, has published a tweet to announce that on August 1, 2002, Back invented something that was later used by the mysterious Satoshi Nakamoto as a foundation for what later became known as Bitcoin.
Curiously, many in the crypto community believe that the cypherpunk legend Adam Back in reality, was Satoshi, the enigmatic inventor of digital gold.
Hashcash celebrates 23rd anniversary
23 years ago, on August 1, young cypherpunk Adam Back, a holder of a PhD in distributed systems from the University of Exeter, the UK, released a whitepaper of his invention – “Hashcash – A Denial of Service Counter-Measure”. Back developed it to combat a rising wave of email spam and denial-of-service attacks. However, the idea was proposed by him a few years earlier, in 1997.
Twenty-three years ago, on August 1, 2002, @adam3us formally released the whitepaper for Hashcash and laid the foundation for Satoshi Nakamoto to create #Bitcoin. pic.twitter.com/crDDOWSC7M
— Samson Mow (@Excellion) August 2, 2025
In Hashcash, the client has to concatenate a random number with a string several times and hash this new string. It then has to do so over and over until a hash beginning with a certain number of zeros is found.
Later on, in 2008, Satoshi Nakamoto adapted the concept first used in Hashcash to establish Bitcoin’s mining proof-of-work mechanism to secure the future BTC network. Satoshi mentioned both Back and Hashcash in the Bitcoin whitepaper released in 2008.
Back denies being Bitcoin inventor
Due to the direct connection of Hashcash and Bitcoin mining proof-of-work system, many came to believe that the mysterious Satoshi Nakamoto was none other than Adam Back himself, who preferred not to be associated with his most famous and revolutionary “invention” anymore.
However, this theory was denied when experts analysed Nakamoto’s writings on the BitcoinTalk forum, comparing them to those of Backs. No similarities were found between the two. However, many still believe that Bitcoin was invented by Adam Back. He continues to deny those claims. Back’s company, Blockstream, came up with the Bitcoin Lightning Network, which allows making mini-Bitcoin payments fast and cheap.