From: Mike Ingle <MIKEINGLE@delphi.com>
Date: Sat, 2 Oct 93 21:38:51 PDT
To: cypherpunks@toad.com
Subject: Offline Digicash ?
Message-ID: <01H3NNHIHQGI90ONDC@delphi.com>
MIME-Version: 1.0
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According to the Chaum-protocol description on chaos.bsu.edu, this is an
online system - both parties must talk to the bank before a transaction is
concluded. Are there any true offline systems? i.e. I can send you an email
which is worth money, with no third parties involved, and there is no audit
trail or means of tracing.

The main problem is that there is no digital "coin" or object which can
be passed around but not duplicated. Other than the bank method, I've read
about an "observer" chip which keeps you honest, but the design of the chip
would have to be secret, or at least the chip would have to know a secret
(i.e. a key) which it would never tell you. If you could extract the key,
you could write a "cheater". Shades of Clipper.

Is there a system which allows anonymity and at the same time prevents
people from double-spending their cash? How does it work?

--- MikeIngle@delphi.com