A Trial Balloon to Ban Email?

[Sunder]

Yes, but how will you stop the spammer from double spending the same $0.25
micropayment on all of his 170,000 email addresses?  Depending on whether
you check that there is a payment attached or not, and also check it with
the bank before delivering it, you'd have already wasted your bandwith and
possibly have accepted a spam into your mail spool.

At that point you have: 

1. already had a slice of your bandwidth eaten by the spammer, plus some
cpu cycles verifying that there exists a coin.  Spammer +1, you -1.

2. You now have to verify that the coin is a coin and not just some random
junk - you waste some cpu cycles here.   If you don't validate that the
coin hasn't been doubly spent, you haven't made that $0.25 and have
accepted a spam - not that you will personally read it, but your system
did (cpu, bandwith and some disk storage until it throws it to the hungry 
maw of /dev/null.)  spammer +1, you -2.

3. Presumably you'll want to validate/cash the coin.  If you do, you'll
need to talk to the bank in order to prevent the spammer from double
spending and to actually collect your quarter v-cash.  By doing that on a
spam, you're taking part of a DDoS against the bank as only the 1st guy on
the spammer's list to talk to the bank will get the coin - because
everyone presumably will chose to cash the coin.  If you don't cash nor
validate the coin with the bank, you haven't made your vquarted, spammer
+10 point, you -1, bank -10,000.


The spammer doesn't give a shit, he just wants to get as many emails out
there as possible.  In fact, he mostly doesn't care whether you filter or
not - he makes his money when he sends the spam, not when you read it.  
Of course, he can charge more for "real, verified" email addresses, but
that's less important.

What's the score again?  Oh yeah, game over, insert quarter to play again.

A beautiful example of creating a cryptographic solution that doesn't
quite work in real life.

----------------------Kaos-Keraunos-Kybernetos---------------------------
 + ^ + :25Kliters anthrax, 38K liters botulinum toxin, 500 tons of   /|\
  \|/  :sarin, mustard and VX gas, mobile bio-weapons labs, nukular /\|/\
<--*-->:weapons.. Reasons for war on Iraq - GWB 2003-01-28 speech.  \/|\/
  /|\  :Found to date: 0.  Cost of war: $800,000,000,000 USD.        \|/
 + v + :           The look on Sadam's face - priceless!       
--------_sunder_ at _sunder_._net_------- http://www.sunder.net ------------

On Tue, 13 May 2003, Declan McCullagh wrote:

> Greg is right, and raises a point I hadn't considered before. But then
> again if I charge $.25 to send me mail in a hypothetical micropayment
> system (and I'd hope a social custom would arise making it tacky to
> retain the money if the mail were not spam), I'd be happy to let
> everyone know I have a working email address.