Re: Hashcash - was re: Spam fights
>>>>> "Russell" == Russell Coker <russell@coker.com.au> writes:
Russell> On Fri, 11 Jun 2004 23:43, shadur@systemec.nl (Rens Houben) wrote:
>> Why bother, when said windows machines will have perfectly good
>> signatures stored on them somewhere already?
Russell> Presumably the signature would be based on the envelope
Russell> recipient and therefore signatures you find on someone else's
Russell> machine would not do any good. If it was otherwise then a
Russell> single signature would work for an entire spam run.
Yes. In hashcash, the hashcash token uses the recipient's address, as
well as a date. The recipient can keep a database of received tokens
to make sure that the same token isn't used twice. Old tokens can be
expired, since the token contains the date too.
--
Hubert Chan <hubert@uhoreg.ca> - http://www.uhoreg.ca/
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