Re: e-postage stamps, was Welcome to the new(ish) ASRG list

>>It's a distributed system with less-than-perfect real-time replication.
>>So maybe 8 or 10 of them verify before every server knows the stamp is
>>used.
>
> I don't think the scale works.  Most payment systems are designed with
> the assumption that most transactions will succeed, with failed ones
> relatively uncommon.  In the e-postage world where 90% of the mail is
> spam, I'd expect 90% of the stamps to be double spent.

If the spammers get hold of every legitimate stamp and re-use it, 8/9 of
spam is still stopped.  If they double-use their own stamps, their costs
for stamps are halved; the business still doesn't work.

> This also has the adverse selection problem, it encourages phishing,
> fake drugs, and other high value spammers who figure that it's just
> a cost of doing business.  Or they set up the First Very Authentic
> E-Postage Bank of Nigeria, and debase the currency.

Why would any ISP consider that bank valid?

Seth