"Eric S. Johansson" <esj@xxxxxxxxxx> writes: > I'm currently looking into using another property of proof of work > puzzles which is that of a reputation proxy. Combining that with a > historically defined reputation of a site, one can use proof of work > as a reputation enhancer for good sites (i.e. guaranteeing delivery to > inbox) and reduce risk to the super enormous bot net (which will have > neutral or bad reputation). This idea strikes me as potentially more successful than proof-of-work-puzzles, which has the large-botnet-vulnerability. Have you thought more about how submission into a reputation proxy would work? That part is a bit sketchy to me, and the main problem seems to be how to avoid submissions from spammers. Seed it with known-good-addresses, and then add new addresses based on who they communicate with? There are also some serious privacy issues here. I do like the general idea of a reputation proxy though. It can be used for a lot of things beyond email, but perhaps the many small details makes it difficult to re-use one reputation proxy for another purpose. /Simon