“ Proof-of-Work ” Proves Not to Work version 0 . 1

  title={“ Proof-of-Work ” Proves Not to Work version 0 . 1},
  author={Ben Laurie and Richard Clayton},
A frequently proposed method of reducing unsolicited bulk email (“spam”) is for senders to pay for each email they send. Proof-ofwork schemes avoid charging real money by requiring senders to demonstrate that they have expended processing time in solving a cryptographic puzzle. We attempt to determine how difficult that puzzle should be so as to be effective in preventing spam. We analyse this both from an economic perspective, “how can we stop it being cost-effective to send spam”, and from a… CONTINUE READING