zcat wrote:
My thoughts, after a 10 minute perusal of hashcash :)
Hashcash is (imho) a stupid waste of time. It unfairly penalises people with slow computers who might want to run a mailing list (me!) while barely slowing any spammer who happens to control a vast network of virus-infected home computers (most of them). And, like most spam 'solutions' it requires a complete reimplimentation of the entire mailsystem.
If you think that 'raising the cost of mail' is the right approach, tiergrube(sp?) would be a much fairer (and more transparent) way of doing it.
To send to a mailing list you only have to hashcash it once (to the mailing list) not once per recipient. Each recipient is expected to accept mail that is correctly hashcash'd to the list. camram suggests that you white list addresses that have previously authenticated. camram also seems to support hashcash. Both systems seem to be improved if you can be sure that the email comes from the person that they claim to, (preferably by GPG or S/MIME, but SPF would also work). While people with older machines may not be able to generate hashcash signatures as fast as someone with a faster computer, how many unique emails do you send? (Remember, with solicited bulk email you only need to generate one code). Even if it took 1s on an older computer, thats still only 3 or 4 emails a second with a top of the line computer. While spam armies can be used against this system for distributed computing, it certainly raises the costs of spamming, when combined with GPG, S/MIME or SPF and perhaps legislation it may raise the cost of spamming to the point that the amount of spam delivered is at manageable levels for most users. And the spam that is delivered will have to be more carefully targeted. (ie, spammers will have to choose which email addresses to spam for the most profit), which means that you should only get spam for products or services you actually care about :)