From: "Perry E. Metzger" <pmetzger@lehman.com>
Date: Mon, 23 Aug 93 19:21:41 PDT
To: hughes@ah.com (Eric Hughes)
Subject: Re: Chaum criticism
In-Reply-To: <9308240153.AA05544@ah.com>
Message-ID: <9308240219.AA26476@snark.lehman.com>
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Eric Hughes says:
> >I am trying to read and understand the Niels Ferguson "Off-line Coins"
> >article, the "Efficient Off-line Digital Cash" paper also from CWI 
> 
> Both articles, as I recall from the abstracts, exist square within the
> observer framework.

I think I have a scheme for real off-line payments, that is, payments
that do not require an observer at the time of transaction (although
they would require a couple of on line transactions in advance). They
would require that people conduct transactions in a style that they
are not used to, but would require no trust and would allow full
anonymity of parties.  

Unfortunately, I don't know enough about the mathematics of Chaum's
blinding schemes to know if the scheme I have in mind (which depends
on his scheme) would work. Could someone point me at a reference or
two on Chaum's original work? The mathematics associated with blinding
is, sadly, something that I haven't spent sufficient time on.

Perry