From: frantz@netcom.com (Bill Frantz)
Date: Thu, 11 Apr 1996 17:31:55 +0800
To: cypherpunks@toad.com
Subject: Re: No matter where you go, there they are.
Message-ID: <199604110019.RAA05628@netcom9.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


At  8:41 AM 4/10/96 -0400, Perry E. Metzger wrote:
Anonymous writes:
> 
> Location-based System Delivers User
> Authentication Breakthrough
> 
> By Dorothy E. Denning and Peter F. MacDoran
> Copyright(c), 1996 - Computer Security Institute - All Rights Reserved
> Top - Help
> 

When I first started reading the paper I said to myself, "Ah, they are
going to have a box that provides digitally signed GPS locations."  I still
think they might try that as plan "B".  Combined with a password or
biometrics to prevent unauthorized use of the box, they might have a
useful, if limited, system.

A few other practical problems with the system they DID describe that
haven't been mentioned:

(1) GPS doesn't work well near the walls of canyons.  The positions
reported can be off by a considerable distance.  This problem probably also
applies in the steel and glass canyons of cities.

(2) Consumer grade GPS receivers have problems acquiring satalites in
forested areas.  The same problem probably will also occur in skyscrapers. 
Using your portable in some client's office will involve shoving an antenna
out the non-openable window.

With these problems, I just can't see GPS authentication being popular for
the masses.  For some military and industrial uses it may solve a real
problem.

Regards - Bill


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