From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <005f01c371df$0e59d5c0$2c9ce541@bl.belllabs.com>
From: "david presotto" <presotto@closedmind.org>
To: <9fans@cse.psu.edu>
References: <200309030059.h830xQj23628@augusta.math.psu.edu>
Subject: Re: [9fans] re: spam filtering fs
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Date: Wed,  3 Sep 2003 01:48:45 -0400
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I'ld rather not have to keep a secret and a counter for everyone I want to
exchange mail with.
Messages get lost and reordered so at the very least I need to accept some
range of possible
sha1ings.  I also want to accept mail from people I haven't talked to before
but have proved
to someone else that they aren't spammers.  I'm happier with the /mail idea
than this one.

----- Original Message -----
From: "Dan Cross" <cross@math.psu.edu>
To: <9fans@cse.psu.edu>
Sent: Tuesday, September 02, 2003 8:59 PM
Subject: Re: [9fans] re: spam filtering fs


> Dave writes:
> > What smime (and pgp) can achieve is digital signing so that spammers
> > can't masquerade with From:'s of people in your white list.
>
> So does having an X-header that has a token in it.  One easy way around
> the harvesting-from-a-mailing-list-archive thing is doing something
> S/Key-ish:  The first time you send an email to someone, send the token
> sha'ed 100,000 times.  The next time, send it sha'ed 99,999 times,
> etc.  Both sides keep track of the token and the current sequence
> number.  Or, and even simpler, take the token and sha it with the
> contents of the message.  The token itself doesn't show up in any
> archives anywhere, and the scheme is immune to problems with bounces
> getting sequence numbers out of whack, and you get some modicum of
> integrity checking on the message itself.  A way around the client
> problem is to build it into the MTA (but the MTA's on both sides have
> to support it).
>
> Ron writes:
> > yeah but ... I don't even want the data coming into my machine. Is that
> > covered too? I really want to get these spammers rejected instantly,
which
> > is why i liked the file system idea.
>
> I think we've lost that battle.  Some knocking at the castle gates
> is always going to happen now days.  :-(
>
> - Dan C.
>
>