Eric S. Johansson writes:
Ben Laurie wrote:
Richard Clayton wrote:
and in these schemes, where does our esteemed moderator get _his_ stamps from ? remember that not all bulk email is spam by any means... or do we end up with whitelists all over the place and the focus of attacks moves to the ingress to the mailing lists :(
He uses the stamp that you generated. Each subscruber adds cryptography@metzdowd.com as an address they receive mail at. Done. Trivial.
take a look at my headers and you'll see a real example.
---eric (No. 1 generator of stamps on the Internet)
It seems like one risk for hashcash is that, when mailing lists are whitelisted, a spammer can then use the lists to amplify spam (which I think is what Richard Clayton was suggesting above). For instance, you generated a single hashcash stamp for cryptography@metzdowd.com of the same value as the stamp you generated for richard@highwayman.com. That stamp would hypothetically induce metzdowd.com to send your message to _all_ of the cryptography subscribers, all of whom have hypothetically whitelisted the list. That means that, if your message were spam, you delivered it to the whole subscriber base at very low cost. Or does hashcash only help moderated mailing lists (where it "pays" the moderator for her time)? My current impression is that it will benefit individual e-mail recipients but not help subscribers to large unmoderated mailing lists. -- Seth David Schoen <schoen@loyalty.org> | Very frankly, I am opposed to people http://www.loyalty.org/~schoen/ | being programmed by others. http://vitanuova.loyalty.org/ | -- Fred Rogers (1928-2003), | 464 U.S. 417, 445 (1984)