From: Hal Finney <hal@rain.org>
Date: Sat, 16 Nov 1996 10:48:22 -0800 (PST)
To: reece@taz.nceye.net
Subject: Re: Remailer Abuse Solutions
Message-ID: <199611161742.JAA01346@crypt.hfinney.com>
MIME-Version: 1.0
Content-Type: text/plain


From: Bryan Reece <reece@taz.nceye.net>
> But what about Okamoto and Ohta's digital cash scheme published in
> Crypto '91?  It appears to be fully untraceable and transferable.  Of
> course, I haven't heard of anyone trying to use this scheme (has it
> been broken?)

This digital cash scheme has a big disadvantage which the authors try
to play down.  The problem is that all spending by a particular user is
linkable.  It can't be connected to his True Name but all of it is
linked, in effect, to his nym.  This is bad because it allows profiling
and dossiers to be built up about nyms with interesting spending patterns,
which could then be used to identify which ones should be candidates
for intensive efforts to discover their identity.

Most other digital cash schemes don't allow linkability of the payor's
activities, which is a much better approach.

Hal