Hashcash is a cryptographic protocol and proof-of-work (PoW) system that was developed by British cryptographer Dr Adam Back to tackle two major issues: email spam and denial-of-service (DoS) attacks. Sending an email or requesting a service. must solve a computational puzzle.
Hashcash is a cryptographic protocol and proof-of-work (PoW) system that was developed by British cryptographer Dr Adam Back to tackle two major issues: email spam and denial-of-service (DoS) attacks. Sending an email or requesting a service. must solve a computational puzzle.
https://coin.news/crypto/demystifying-hashcash-the-precursor-to-bitcoin-explained/