Pay-for-email plan taps computational resources
Researchers at Microsoft have come up with a novel approach to reducing spam by making emailers pay for postage with computation resources. The system works by forcing email senders to solve a cryptographic puzzle for every email they wish to send; puzzles take 10 to 20 seconds to solve, dramatically reducing the amount of email a single machine can send in a given day.
"If I don't know you, I have to prove to you that I have spent a little bit of time in resources to send you that e-mail.
"When you see that proof, you treat that message with more priority."
Of course, any pay-for-email scheme will need widespread adoption to have a major impact on the volume of unsolicited junk mail. Forcing spammers to pay for email with computational resources may encourage efforts to hijack insecure PCs for their potential puzzle-crunching power, too.