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Friday, January 18, 2013

Cyber Attack


The H Security has a good synopsis of a story on Defense News. They are talking about people messing about with radios, trying to inject code/data into stone walled computers. It sounds impossible, but then I never thought they would be able to use radar to look through walls. I understand that it is theoretically possible to figure out what somebody is typing by detecting the minute radio signals emanating from the wire that connects your keyboard to the computer. A wire is basically an antennae, and changes in voltage are going to produce radio frequency, well, maybe not signals, but some kind of noise. I imagine if you listen to enough of that noise, and you've got some whiz kids writing DSP (Digital Signal Processing) code, you could probably listen in on that wire and figure out what someone is typing without having to actually touch it. How close you would have to be is, well, maybe not unknown, but undoubtedly classified. Many moons ago, back during the cold war, the CIA had a project where they inserted a listening device underneath a Soviet undersea communication cable. They seem to be very happy about all the information they got from that program. I think it kept a large number of people very busy for a long time, which is always a good thing. Probably advanced the state of the art while they were at it.
    So they can listen to what you are typing and using similar techniques, they can also figure out what is being displayed on your monitor, but going the other way? That could be a bit of a trick. You can induce a signal in a wire. That's basically what radio and television broadcasting does, they are sending electromagnetic energy out through the air and wherever it impacts a metal object it is going to generate a small amount of electricity. Metal objects like radio and TV antennaes, which are connected to radio and TV receivers. These receivers are looking for a specific signal, teasing it out of all the surrounding noise, and then amplifying it enough so that it can be heard. But how much power would you need to induce a signal that would be strong enough to be detected by the transistors in a computer? Radio signals coming out of an antennae are measured in microvolts. Internal computer voltages are measured in, well, it used to be volts, but now it is more like tenths of a volt. Still, a tenth of a volt is a heck of a long way from a microvolt.

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