nonintrusive signal sniffing

signals on

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can get

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to

I bet they won't tell you that on a public forum

We will never know.

law

classes

signals on

One

Take a spectrum analyzer. Wave the probe near your signal line of interest. Report your results.

I donot remember enough of grad electronics to know whether this is feasible or not - it is just an idea you could work upon. You can try two things:

1)You may "touch" the cable to measure provided you use a home-made probe/scope with its load adjusted such that it makes very less difference to the source whether the actual termination is connected or the termination plus the probe. 2)You can measure the complete load ( resistive plus reactive) presented by your sink circuit to the source - then you can model a pobe/meter with the same load and connect it thus dispensing of the actual sink ciruit completely.

On the overall scheme of sniffing what you ask is trivial. If you want a challenge try for a non-intrusive sniff of a fiber optic cable. What you see on the tv and movies is mostly fiction, but remember truth is much stranger than fiction.

Check out this Tempest site:

Around 15 years ago the US govt. greatly scaled back the number of locations that needed Tempest certified equipment and mostly killed off the market for producing really quiet equipment. The need and market still exist. If you are interested in pursuing this field check with your professors that specialize in RF. They will probably know enough to point you in the right direction.

--
Scott
Validated Software Corp.

Google for 'tempest security' as a starting point. It's not specifically directed at wires, but the concept is extensible.

"Oscar" wrote: >

I don't think dispensing of the actual sink is non-intrusive. ;-)

Thad

You should at least learn a few of the terms used in the electronic security field, else you'll have no more influence than a storm in a teapot.

You've never got a bunch of parts at Radio Shack and played around with them? Know how to make circuit to flash an LED?

I've got some ideas how to do these things (the things you ask about, as well as making circuits that flash LED's), which might or might not be worth anything, but I won't share them with strangers on the Internet (well, I might share how to make an LED flashing circuit).

I recall seeing a movie (I don't recall the name, this was on TV in the US at least 20 years ago) involving some sort of bank or jewelry heist. Two guys synchronized their watches. Later, at the very moment when one got the attention of a security guard whose job was to (among other things) keep an eye on a "CCTV" [such an old-fashioned term] monitor connected to a camera elsewhere in the building, the other guy was in a utility room cutting the video cable and splicing in the output of a VCR which was playing a recording of the camera from a few days earlier. The first guy successfully kept the guard's eyes away from the monitor while it had 'snow' on it, and they pulled it off. The guard even got a call about a possible problem when the robbery was going on, and he said "I don't see any problem, things look fine to me." The moral of that movie is: Don't dismiss or ignore the power of social engineering.

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You should at least learn a few of the terms used in the electronic security field, else you'll have no more influence than a storm in a teapot.

You've never got a bunch of parts at Radio Shack and played around with them? Know how to make circuit to flash an LED?

I've got some ideas how to do these things (the things you ask about, as well as making circuits that flash LED's), which might or might not be worth anything, but I won't share them with strangers on the Internet (well, I might share how to make an LED flashing circuit).

I recall seeing a movie (I don't recall the name, this was on TV in the US at least 20 years ago) involving some sort of bank or jewelry heist. Two guys synchronized their watches. Later, at the very moment when one got the attention of a security guard whose job was to (among other things) keep an eye on a "CCTV" [such an old-fashioned term] monitor connected to a camera elsewhere in the building, the other guy was in a utility room cutting the video cable and splicing in the output of a VCR which was playing a recording of the camera from a few days earlier. The first guy successfully kept the guard's eyes away from the monitor while it had 'snow' on it, and they pulled it off. The guard even got a call about a possible problem when the robbery was going on, and he said "I don't see any problem, things look fine to me." The moral of that movie is: Don't dismiss or ignore the power of social engineering.

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