CentMail: Rate Limiting via Certified Micro-Donations
Sharad Goel, Jake M. Hofman, John C. Langford, David M. Pennock, Daniel M. Reeves · 2009
The Internet has reduced the cost of communication to near zero, benefiting billions of people around the world. One consequence, however, is that unsolicited and unaccountable commercial communication, or spam, is also sent