Hashcash
- Date
- 1997 · confidence medium
- Place
- Cambridge, United Kingdom
- Credited to
- Adam Back
- Field
- Knowledge & symbols
What it is
A proof-of-work system requiring an expensive hash computation to curb email spam and denial-of-service attacks, proposed by Adam Back and later the direct model for Bitcoin's mining mechanism.
What it led to
- direct precursor of Bitcoin's proof-of-work
- spam mitigation through computational cost
- inspiration for other computation-based anti-abuse systems
- development of proof-of-work-based tokens and currencies