Re: All our eggs in one basket?

Although Jim's protocol doesn't quite work, as Eric pointed out, because
of the re-blinding, it does suggest another approach.  If the bank sent
you a coin and you claim you never got it (maybe you're telling the truth,
maybe not), they can just send it again.  You can't cheat because at best
this will allow you to get two copies of the same coin.

Contrariwise, if the bank cheats and never sends you the coin, just ask
them to send it again.  They have no basis for refusal.

Here we see a case where the ease of duplication of digital money is
actually an advantage, rather than the disadvantage it usually seems
to be.

Hal Finney
hfinney@shell.portal.com

.

>If the bank sent
>you a coin and you claim you never got it (maybe you're telling the truth,
>maybe not), they can just send it again.  

In fact, if the bank signs a committment to give you a particular
coin, the bank can't claim to have never received your request.  For
high value transactions where timeliness is a concern, this prevents
the bank from claiming that they didn't get the original request and
thus making a "delay of service" attack against you.  Delay of service
is the denial of the service of timeliness.

Eric