Re: [Asrg] An Anti-Spam Heuristic

John Leslie <> Thu, 13 December 2012 19:02 UTC

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Date: Thu, 13 Dec 2012 14:02:51 -0500
From: John Leslie <>
To: Anti-Spam Research Group - IRTF <>
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Subject: Re: [Asrg] An Anti-Spam Heuristic
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Bart Schaefer <> wrote:
> On Dec 13,  9:03am, Rich Kulawiec wrote:
>} [Adam Sobieski <> wrote:]
>}> A number of heuristics include increasing the computation required to
>}> send and receive an email, for example one to a few minutes of computation
>}> per email on desktop computers.
>} I don't think you can do this.  I think you're trying to drown someone
>} who owns the ocean, and that the attempt is futile.  But perhaps you have
>} an approach that's eluded others, that overcomes the obvious problems,
>} and I just don't see it yet due to insufficient caffeine intake.

   It's not sufficient to prove some value was expended: something of value
must be transferred to the receiving SMTP server (if not all the way to
the reader).

> Generating "cash" with computing resources means they can print all the
> money they want.  For a pay-to-play scheme to have any hope of working,
> it needs to be based on a resource that can be controlled from outside.

   I'm not sure "controlled from outside" can work...

> Which leads to the same discussion we had four years ago.  Today is the
> anniversary of
> which never went went anywhere beyond that.

   Indeed it is, Bart! I'll treat you and Ben to a virtual beverage and
four virtual candles. ;^)

> It is acknowledged that the bad guys can steal postage from a zombied
> system almost as easily as they can steal compute resources, but it's
> easier to discover and react to the theft of something that doesn't
> invisibly regenerate.

   It's better yet to react to actual value received. ;^)

   The snail-mail systems _are_ sender-pays systems, but it's only the
perceived value-received that causes snail-mail recipients to open an

   (I'm not holding my breath on anything happening with ePostage, but
I remain willing to work with anybody else with the energy to pursue it.)

John Leslie <>