From: pete@cirrus.com (Pete Carpenter)
Date: Fri, 26 Mar 93 12:51:45 PST
To: grady@public.btr.com
Subject: Re:  TEMPEST in a teapot
Message-ID: <9303262028.AA11335@ss2138.cirrus.com>
MIME-Version: 1.0
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It is speculated that poorly protected systems can
be effectively monitored up to the order of one kilometer from the target
equipment.

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The "readability" of the relatively high energy sweeps in a standard CRT monitor
is well known. Any idea of similar effects on LCD screens ?  The energy involved
would be orders of magnitude less, just for starters.  Also, since the whole screen
is effectively oscillating, I'm not sure that there is any 'raster' sweep per se
going on here at all.  This could be a factor for the truly paranoid :-) using 
portables with LCD screens.


Pete Carpenter                           pete@cirrus.com
                                
Talk about your plenty, talk about your ills,
One man gathers what another man spills. - Robert Hunter