RE: Optical Tempest FAQ
IMHO, if you light up two or more other identical CRT's and have them display random junk it should throw enough noise to make it worthless - (and would put out enough similar RF to mess with RF tempest) there might be ways to filter the photons from the other monitors out, but, it would be difficult. --Kaos-Keraunos-Kybernetos--- + ^ + :Our enemies are innovative and resourceful, and so are we. /|\ \|/ :They never stop thinking about new ways to harm our country /\|/\ --*--:and our people, and neither do we. -G. W. Bush, 2004.08.05 \/|\/ /|\ : \|/ + v + :War is Peace, freedom is slavery, Bush is President. - On Thu, 2 Dec 2004, Tyler Durden wrote: Interesting. Contrary to what I thought (or what has been discussed here), only a 'scalar' of detected light is needed, not a vector. In other words, merely measuring overall radiated intensity over time seems to be sufficient to recover the message. This means that certain types of diffusive materials will not necessarily mitigate against this kind of eavesdropping. However, his discussion would indicate that the various practical concerns and limitations probably limit this to very niche-type applications...I'd bet that it's very rare when such a trechnique is both needed as well as useful, given the time, the subject and the place. -TD From: Sunder [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Optical Tempest FAQ Date: Thu, 2 Dec 2004 10:27:04 -0500 (est) http://www.cl.cam.ac.uk/~mgk25/emsec/optical-faq.html Along with tips and examples. Enjoy, and don't use a CRT in the dark. :-)
Re: Optical Tempest FAQ
Well, the first one's a little Hey this is scary give us some grant money-ish. This has zero impact on real-world telecom systems in terms of detecting actual payloads BUT detecting some of the management channel info (via the external DS1 management channel) could actually matter in some cases. I'm still waiting for someone to put a trojan into the telecom control channels causing them to randomly reprovision themselves. That could have an impact that far exceeds mere PR... -TD From: Chris Kuethe [EMAIL PROTECTED] Reply-To: Chris Kuethe [EMAIL PROTECTED] To: [EMAIL PROTECTED] CC: Tyler Durden [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] Subject: Re: Optical Tempest FAQ Date: Thu, 2 Dec 2004 23:39:33 -0700 On Fri, 3 Dec 2004 01:01:57 -0500, Dave Emery [EMAIL PROTECTED] wrote: ... In fact the greater hazard may sometimes be from red, yellow or green LEDs on the front of equipment that are directly driven with real data in order to allow troubleshooting - recovering data from one of those at a distance using a good telescope may be possible and most people don't think of the gentle flicker of the LED as carrying actual information that could be intercepted. Like this classic. Was just as much fun to reread as it was the first time. :) http://www.google.ca/search?q=cache:YdHPMAbPMeAJ:www.applied-math.org/optical_tempest.pdf+black+tape+over+modem+lights+tempesthl=enclient=firefox http://www.applied-math.org/optical_tempest.pdf -- GDB has a 'break' feature; why doesn't it have 'fix' too?
Re: Optical Tempest FAQ
On Thu, Dec 02, 2004 at 12:32:09PM -0500, Tyler Durden wrote: However, his discussion would indicate that the various practical concerns and limitations probably limit this to very niche-type applications...I'd bet that it's very rare when such a trechnique is both needed as well as useful, given the time, the subject and the place. -TD The big problem with this technology (and classic Van Eck electromagnetic interception too) is that more and more folks are using LCD screens or other display devices that do not do single thread raster scans of what they are displaying. Thus no single signal exists to detect with all the pixels of the image in it. In fact the greater hazard may sometimes be from red, yellow or green LEDs on the front of equipment that are directly driven with real data in order to allow troubleshooting - recovering data from one of those at a distance using a good telescope may be possible and most people don't think of the gentle flicker of the LED as carrying actual information that could be intercepted. -- Dave Emery N1PRE, [EMAIL PROTECTED] DIE Consulting, Weston, Mass 02493
Optical Tempest FAQ
http://www.cl.cam.ac.uk/~mgk25/emsec/optical-faq.html Along with tips and examples. Enjoy, and don't use a CRT in the dark. :-) --Kaos-Keraunos-Kybernetos--- + ^ + :Our enemies are innovative and resourceful, and so are we. /|\ \|/ :They never stop thinking about new ways to harm our country /\|/\ --*--:and our people, and neither do we. -G. W. Bush, 2004.08.05 \/|\/ /|\ : \|/ + v + :War is Peace, freedom is slavery, Bush is President. -
RE: Optical Tempest FAQ
Interesting. Contrary to what I thought (or what has been discussed here), only a 'scalar' of detected light is needed, not a vector. In other words, merely measuring overall radiated intensity over time seems to be sufficient to recover the message. This means that certain types of diffusive materials will not necessarily mitigate against this kind of eavesdropping. However, his discussion would indicate that the various practical concerns and limitations probably limit this to very niche-type applications...I'd bet that it's very rare when such a trechnique is both needed as well as useful, given the time, the subject and the place. -TD From: Sunder [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: Optical Tempest FAQ Date: Thu, 2 Dec 2004 10:27:04 -0500 (est) http://www.cl.cam.ac.uk/~mgk25/emsec/optical-faq.html Along with tips and examples. Enjoy, and don't use a CRT in the dark. :-) --Kaos-Keraunos-Kybernetos--- + ^ + :Our enemies are innovative and resourceful, and so are we. /|\ \|/ :They never stop thinking about new ways to harm our country /\|/\ --*--:and our people, and neither do we. -G. W. Bush, 2004.08.05 \/|\/ /|\ : \|/ + v + :War is Peace, freedom is slavery, Bush is President. -
