Forwarded message:
Subject: Re: Laptop TEMPEST From: Ryan Lackey <rdl@mit.edu> Date: 09 Feb 1998 02:34:15 -0500
FCC RF/EMC testing is well nigh useless for TEMPEST protection.
I disagree, it would give you a gross baseline on the total emissions between monitors and laptops. That field strenght measurement would at least allow you to calculate radiuses of equal strength to calculate approximately how far the emissions are from each class of device for equal probabilities of detection. One of the specific goals is to measure how effective the device is at effecting other co-located devices (such as seeing ghost images on other monitors or causing static in paging equipment). I suspect one could do it with a spectrum analyzer or a grid dip meter.
I imagine there may be some other "dual use" technologies through for testing TEMPEST equipment. Perhaps some medical equipment has stringent stray emanation specs?
We're not trying to bring the individual vertical retraces out of the chaff...we're trying to calculate the total comparitive emission strengths. If that isn't high enough then trying to get individual componants of that field will be useless. ____________________________________________________________________ | | | The most powerful passion in life is not love or hate, | | but the desire to edit somebody elses words. | | | | Sign in Ed Barsis' office | | | | _____ The Armadillo Group | | ,::////;::-. Austin, Tx. USA | | /:'///// ``::>/|/ http://www.ssz.com/ | | .', |||| `/( e\ | | -====~~mm-'`-```-mm --'- Jim Choate | | ravage@ssz.com | | 512-451-7087 | |____________________________________________________________________|