Adam Back
Hashcash's proof-of-work idea became the foundation of Bitcoin mining and of anti-spam and anti-abuse rate limiting.
Adam Back is a British cryptographer and cypherpunk. He earned a PhD in computer science from the University of Exeter and was an active participant in the cypherpunks mailing list in the 1990s.
Hashcash
In 1997 Back proposed Hashcash, a scheme in which a sender proves it has spent CPU time by finding a partial hash collision. Intended to throttle email spam and denial-of-service, it was later cited by Satoshi Nakamoto's Bitcoin whitepaper as the basis of Bitcoin's proof-of-work mining.
Export-control activism
Back was among the cypherpunks who protested U.S. cryptography export rules by circulating a three-line Perl implementation of RSA, printed on T-shirts and email signatures as a "munition." In 2014 he co-founded Blockstream, where he serves as CEO.
Timeline
- 1970-07Born in London.
- 1997-03Announces Hashcash on the cypherpunks mailing list.
- 2002Publishes 'Hashcash - A Denial of Service Counter-Measure'.
- 2008-10-31Hashcash is cited in the Bitcoin whitepaper.
- 2014Co-founds Blockstream.
Adam Back
- Type
- Person
- Era
- 1990s-present
- Born
- 1970
- Known for
- Hashcash (1997); Blockstream co-founder; Cypherpunk activism against export controls
- Tags
- cypherpunks, hashcash, proof-of-work, cryptography, bitcoin
Created by Joas A Santos · Something wrong or want it removed? Open an issue.