From: "Perry E. Metzger" <perry@snark.imsi.com>
Date: Fri, 6 May 94 04:15:50 PDT
To: Matthew J Ghio <mg5n+@andrew.cmu.edu>
Subject: Re: Marked_Money
In-Reply-To: <whmO4aK00awHAs6EZr@andrew.cmu.edu>
Message-ID: <9405061115.AA00728@snark.imsi.com>
MIME-Version: 1.0
Content-Type: text/plain



Matthew J Ghio says:
> >         Is there a way of marking digital coins, so the depositor
> > can be identified?
> 
> Only if the depositor marks them as such.  The depositor generates the
> coin, and gives it to the bank to sign it.  The bank signs it in
> exchange for another valid signed token.  The bank can't alter it in any
> way, the bank can only sign it.

You have the protocol reversed. It is the person who withdraws the
money who blinds a coin. Depositors can indeed be tracked by collusion
between the person minting the coin and the bank, but in practice this
would not be a problem.

Perry