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Your computer is never secure

D

David Robbins

Jan 1, 1970
0
Cotton eye joe said:
My question is are they seeing my monitor via the emission for the monitor its self
signal coming from the cabling? And if for some reason they have it hard wired, is
there a way to detect that? Any defensive measures I can take to defend a hard wire
or a remote tap?

who is seeing your monitor??
 
K

Keith R. Williams

Jan 1, 1970
0
jimp@specsol-spam- said:
TEMPEST technology is classified.

Actually the technology isn't classified. Indeed it's rather
well known. The TEMPEST *specification* is classified. You may
get a pass/fail from testing, but you don't know what the test
is. One can reasonably figure out what to do to pass without
knowing the criteria though. BTDT, and passed.
Have you a clue on the repercussions of leaking classified information?

If one has no security clearance, none. One cannot leak what one
doesn't have. If it was leaked to you by someone with said
clearance, they may be in in deep kaka, but not Joe Citizen.
(See: Pentagon Papers).
 
K

Keith R. Williams

Jan 1, 1970
0
My question is are they seeing my monitor via the emission for the monitor its self
signal coming from the cabling?

The classical attack is off the monitor itself (cables are
relatively easy to shield). There is a significant beam current
in the CRT, which can be monitored from quite a distance. So I'm
told, this can even be singled out from within a field of a
thousand other similar monitors, given the proper incentive.
And if for some reason they have it hard wired, is
there a way to detect that?

The problem is size of the monitor and the open glass in the
front, as well as the rather high beam current. There is also
the coupling to the power source. These are far larger issues
than the transmission lines to the monitor.
Any defensive measures I can take to defend a hard wire
or a remote tap?

Tinfoil hat.
 
C

Cotton eye joe

Jan 1, 1970
0
David Robbins said:
who is seeing your monitor??
I am leary to say but it cant be any further out than some of the items discussions I
have read here. I have a situation where my agressors, perps, whatever are operating
from two houses whose back yards back up to a road. We live accross the road and up
on a knoll. Keep in mind they don't really have yards just a large common heavily
wooded area. I have some pretty powerful PTZ dome cams that allows me to monitor a
large area surrounding my house maybe a half mile optically zoomed.

When there is a disturbance say, around the pool area and I pan over to it, I will
hear a loud knocking coming from across the rd as if to warn the intruder. It's been
almost two years now and there is no doubt they view my monitor. None what so ever. I
have several photos of an individual sitting on an observation platform in the
wooded area who is sitting and staring into a monitor, maybe a half a dozen shots.
Its a field monitor, an old one like I have used in the military, complete with side
visors sitting on a three legged stand. Every time we have focused on one they
quickly turn it off. Except for once when it was sitting unattended for several
minutes before someone walked over and pulled the plug. Yes absolutely they see it.
Even when I use a spot monitor in a vault with the main monitor off.

CEJ
 
C

Cotton eye joe

Jan 1, 1970
0
Keith R. Williams said:
The classical attack is off the monitor itself (cables are
relatively easy to shield). There is a significant beam current
in the CRT, which can be monitored from quite a distance. So I'm
told, this can even be singled out from within a field of a
thousand other similar monitors, given the proper incentive.


The problem is size of the monitor and the open glass in the
front, as well as the rather high beam current. There is also
the coupling to the power source. These are far larger issues
than the transmission lines to the monitor.


Tinfoil hat.

Keith,
Very funny, your a laugh a minute, but seriously I am using a 20" Sony with a
massive glass front along with an 18" Panasonic for a spot monitor. Would
an LCD be harder to get a read on?
Is there a type of screen, coating or similar material that can be applied
to nix the emissions that you are aware of, besides the foil hat of course.

CEJ
 
B

Baphomet

Jan 1, 1970
0
Cotton eye joe said:
I am leary to say but it cant be any further out than some of the items discussions I
have read here. I have a situation where my agressors, perps, whatever are operating
from two houses whose back yards back up to a road. We live accross the road and up
on a knoll. Keep in mind they don't really have yards just a large common heavily
wooded area. I have some pretty powerful PTZ dome cams that allows me to monitor a
large area surrounding my house maybe a half mile optically zoomed.

When there is a disturbance say, around the pool area and I pan over to it, I will
hear a loud knocking coming from across the rd as if to warn the intruder. It's been
almost two years now and there is no doubt they view my monitor. None what so ever. I
have several photos of an individual sitting on an observation platform in the
wooded area who is sitting and staring into a monitor, maybe a half a dozen shots.
Its a field monitor, an old one like I have used in the military, complete with side
visors sitting on a three legged stand. Every time we have focused on one they
quickly turn it off. Except for once when it was sitting unattended for several
minutes before someone walked over and pulled the plug. Yes absolutely they see it.
Even when I use a spot monitor in a vault with the main monitor off.

CEJ

Joe -

What the hell are you into that the existential "THEY" would be monitoring
you?
 
D

Dr Engelbert Buxbaum

Jan 1, 1970
0
Baphomet said:
Wouldn't the receiver have to be in relatively close proximity to the
monitor? Computers, monitors et al are not designed to be transmitters, even
though they all emit some spurious electromagnetic radiation.


That depends on what you call close. There has been some discussion in
security circles about so-called TEMPEST-attacs for example in
industrial espionage, BSI (the German Federal Office for Security in
Information Technology) has looked into that a couple of years back.
Sensitive, commercially available receivers can pick up signals from a
monitor over several hundred meters, depending on building standards and
the number of CRTs in use.

There are a couple of soultions to the problem:

1) perimeter security: don't let anybody get close enough

2) shielding and filtering: TEMPEST-proof equipment is sold for example
to the military and similar sensitive institutions (at a price, of
course)

3) The use of special fonts, which do not have sharp black/white
transitions

4) Use TFT screens, which send out little ratiation. Today probably the
cheapest option.
 
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