Security Basics mailing list archives

RE: Seeking a solution for detecting hidden cameras


From: "Steven Hess" <shess () myrapidsys com>
Date: Tue, 13 Mar 2007 11:51:41 -0400

Hello:

Some additional information. 

The wire mesh, if grounded, will attenuate wireless RF signals, depending on
the frequency and the size of the "holes" in the mesh. Google "Faraday Cage"
for more information. If you want to see a good example - the window on a
microwave oven allows light to pass, but blocks the 2140 MHz used by the
oven. Note that the coverage is a bit better than a screen, though. The
frequency of a microwave oven is close to the 2.4 GHz used by 802.11b/g but
is not the same as the 5 gig used by 802.11a

Higher frequencies need smaller holes = better attenuation. 

Detectors of tube type cameras used the fact that the magnetic deflection
coils used in scanning the image, were running at a multiple of the
horizontal scanning rate. This produces a detectable EMF signal. CCD pickups
use much less power, and dump row data at a different frequencies depending
on the size and megapixel of the pickup, and are very hard to detect by
spurious emissions. 

In my opinion, the best way to prevent this kind of intrusion, is to build a
zone around the dressing room, where inspection of surfaces is possible.
Alarm this area. Checking for wires and cameras on the inside walls is then
a management responsibility. The wire mesh is a possibility, and could be
retrofitted, but is not the complete answer. 

Steven Hess CPBE
WFTT-TV



-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com] On
Behalf Of Pranav Lal
Sent: Monday, March 12, 2007 8:56 PM
To: security-basics () securityfocus com
Subject: RE: Seeking a solution for detecting hidden cameras

Could such a mesh be installed in an already constructed structure like a
shopping maul? 

-----Original Message-----
From: Mondragon, Todd [mailto:todd.mondragon () fmr com]
Sent: Monday, March 12, 2007 9:30 PM
To: Murda Mcloud; Pranav Lal; security-basics () securityfocus com
Subject: RE: Seeking a solution for detecting hidden cameras

No need to jam, a wire mesh placed in the walls and grounded will stop most
RF devices cold.
The mesh should be of the same type as screen door mesh (must be wire
though!) to be able to stop any 2ghz signals. The mesh would also need to be
electrically contiguous of course.

Might make it hard to drill as well, the mesh would foul any powered bits
and a hand tool would have great difficulty dealing with it as well.

Todd Mondragon

-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com]
On Behalf Of Murda Mcloud
Sent: Sunday, March 11, 2007 7:53 PM
To: 'Pranav Lal'; security-basics () securityfocus com
Subject: RE: Seeking a solution for detecting hidden cameras


One thing to do would be to build the room as clean and free from places
that cameras could be hidden etc. ie no benches etc. Make it so that any
tampering would be obvious.
Also, make the walls etc out of something that would be hard to drill a
pinhole in.

Then some of those detectors that you listed could be used-though I can't
vouch for any of them.
Maybe there's a way of jamming signals too?

-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com]
On
Behalf Of Pranav Lal
Sent: Friday, March 09, 2007 6:08 PM
To: security-basics () securityfocus com
Subject: Seeking a solution for detecting hidden cameras

Hi all,

I have been asked by a client to find a solution for detecting cameras in
dressing rooms etc. The client has trial rooms where customers can try
various garments. The concern is that  some one could plant a camera in one
of these rooms and photograph customers.

I have checked online and have found the following sources;
http://www.brickhousesecurity.com/sf-103.html
http://www.spytechs.com/bug_sweep_equip/vcd_43.htm
http://www.pimall.com/nais/countervideo.html
http://www.intpro.co.uk/pinhole.htm
http://www.intpro.co.uk/camera%20detector.htm
Are there any others? Has any one on this list tried any such solutions? I
have found an interesting reference on hiding and detecting cameras at
http://www.tentacle.franken.de/papers/hiddencams.pdf

Pranav



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