Re: [ANNOUNCE] contrib/hashcash.el spam fighter

[David Masterson <dsm@rawbw.com>]

>>>>> Stainless Steel Rat writes:

> * Simon Josefsson <jas@extundo.com>  on Sun, 23 Jun 2002

> | Pregenerated or not, the computation of the field requires someone
> | to burn CPU time, if the limit is set sufficiently high spammers
> | will find it costs too much to send spam, which is the point.

> For the sake of argument, say that hashcash.el users want a 128 bit
> hash.  Today I calculate a 128 bit hash and send out a million
> messages using that hash in the X-Hashcash header.  Tomorow I
> generate a new 128 bit hash so that the old one is no longer useful
> as filter bait, and send out another million messages.  I repeat
> this cycle indefinitely.

> Please explain to me where in this scheme I am burning any
> significant CPU time generating hashes, or how it forces the spammer
> to do more work than the recipients, because I cannot see it.

Is that the method of using hashcash?  It would seem for it to be used
as postage, the hash would have to be calculated for each person you
(the spammer) want to send email to (assuming everyone was requiring
postage).  Therefore, it's not compute 1 128-bit hash and send out a
million messages, but rather compute a million 128-bit hashes to apply
to each message.

-- 
David Masterson
dsm@rawbw.com