From: Anonymous <anon@anon.efga.org>
Date: Tue, 30 Sep 1997 05:48:18 +0800
To: cypherpunks@cyberpass.net
Subject: Re: Remailers and ecash
Message-ID: <cdc554c742ae256c8ca80bf6f75d2f20@anon.efga.org>
MIME-Version: 1.0
Content-Type: text/plain



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Lucky Green wrote:
>There are a number of technical reasons why you really don't want to
>call the standard commandline Ecash client from a script to
>add/retrieve Ecash from Mixmaster remailer packets. The biggest
>problem being that you can fit only a few coins into the packet
>header as specified. There is no feature in the standard Ecash client
>that allows coin level control. DigiCash firmly resited and continues
>to resist adding it. A $0.25 payment could be paid as three coins or
>as 25 coins. The user has no control over this. For this and a number
>of other reasons, DigiCash's software is unsuitable for the task.

I've thought about this and I don't believe that it is a brick wall.

If the mixmaster remailers charged the smallest coin Mark Twain Bank
issues, then you would always get one coin and it would fit into the
packet.  I'm guessing this is a penny.  While this is not the ideal
method for deciding pricing, it would certainly work.

Even for larger amounts, there's probably a way to trick the Digicash
software into giving you the coins you want.  Let's say you are trying
to generate a pile of certificates in a certain amount that have less
than a certain size.  If you keep withdrawing the money and
redepositing it, you can keep the certificates which are the right
size and throw back the ones that aren't.  (You might have to find a
way to shake things up by depositing and withdrawing various amounts.)

There's probably a better way to do this.  For instance, we might
observe that every time ten dollars were withdrawn from the bank and a
certificate was generated for 25 cents, it only used three coins.  So,
we withdraw ten dollars, issue a 25 cent certificate, put back the
remaining amount, withdraw ten dollars, get another 25 cent
certificate, etc.  This is easily automated, of course.

Question: Where is the coin issuing decision made?  I assume that it
is made in the client software.  This, of course, is not under the
control of Digicash or Mark Twain bank.

Conclusion: Mixmaster remailers can probably use ecash with just a
little more work.

Monty Cantsin
Editor in Chief
Smile Magazine
http://www.neoism.org/squares/smile_index.html
http://www.neoism.org/squares/cantsin_10.html


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