From: elee9sf@Menudo.UH.EDU
Date: Wed, 21 Jul 93 15:20:58 PDT
To: cypherpunks@toad.com
Subject: ANON: Re: remail abuse
In-Reply-To: <9307212036.AA17170@indirect.com>
Message-ID: <199307212220.AA24582@Menudo.UH.EDU>
MIME-Version: 1.0
Content-Type: text/plain



> I'm sure that would be a big help, although I'm not literate enough yet in
> the area of digital cash to understand how this would work.

Okay - actually, you don't need to be very familiar with digital cash
at all.  Just think of a cash accepting remailer as one in which you
are charged a fee for each use.  Similar to postage stamps and postal
mail.  When you want to use a digital cash accepting remailer, you
would first purchase some postage stamps, certificates, however you
want to think of it.  Then, you attach the cash/stamp/certificate to
the mail (maybe by a special header field), and send it to the
remailer.  Your mail would probably be encrypted as well to keep
others from spying on your cash, altering it (rendering it invalid)
and using it for themselves.  The remailer would validate your cash,
probably store it in a file to prevent multiple uses, and then forward
your mail to wherever.

The digital cash part just means electronic forms of payment which
have cash properties.  Say you purchase something with cash.  The
merchant can't link your identity to the cash, and later when the
merchant deposits cash in a bank, the bank cannot link the cash to
your transactions with the merchant.  But the merchant can verify the
cash is valid, and the bank can too.  Furthermore, you can't spend the
same piece of cash twice.

This is confusing to think about without being familiar with modern
crypto; one of these days I shall finish a digital cash application
I've been working on for people to play with.

/-----------------------------------\
| Karl L. Barrus                    |
| elee9sf@menudo.uh.edu             | <- preferred address
| barrus@tree.egr.uh.edu (NeXTMail) |
\-----------------------------------/