[91780] in Cypherpunks
Re: remailer hashcash spam prevention
daemon@ATHENA.MIT.EDU (Steve Schear)
Sat Dec 13 16:05:44 1997
In-Reply-To: <199712131055.KAA00967@server.eternity.org>
Date: Sat, 13 Dec 1997 10:27:22 -0800
To: Adam Back <aba@dcs.ex.ac.uk>
From: Steve Schear <schear@lvdi.net>
Cc: cypherpunks@cyberpass.net
Reply-To: Steve Schear <schear@lvdi.net>
I disagree that the best way to implement hashcash is solely via the SMTP=
mechanism. =20
Almost any efficient hashcash mechanism will require some sort of history=
file, or "invited list," to allow mail lists and those we have corresponded=
with to continue to do so w/i having to supply hashcash each time. This=
list contains information which might have privacy implications and so=
should not be stored at the ISP, which can be forced to reveal such info=
w/o the knowledge of the client.
If 'open' list policies were changed so that anyone could post if they=
supplied enough hashcash for each mailing list recipient for their first 1=
or 2 posts, and thereafter no longer needed to supply hashcash (sort of=
minimum reputation capital), it might eliminate hit-and-run or throw-away=
account SPAMers without offering too high a hurdle to new or infrequent pos=
ters.
Since most popular email clients allow plug-ins (e.g. Eudora) or extensions=
via Java/ActiveX, providing hashcash functionality via a plug-in and the=
java generators you propose would provide a simple mechanism to test its=
effectiveness w/o needing to involve the IETF. The shortcoming of a=
plug-in approach is that few newbies will know of it or install it and will=
therefore have to wait till its built into the new release of whatever=
client they use or until some or all of the features are supplied by their=
ISP, allowing those calling regulation to continue to blow their horns. =
However, if after a successful cypherpunk beta we could get the major email=
client companies (Netscape, M$ and Qualcomm) to include our plug-ins with=
all their new updates and offer them for free download from their Web=
sites, it could quickly steal the CAUCE folk's thunder.
--Steve
