> I'm actually interested in detecting LCD and CRT leakage, and decoding > the picture display from both LCDs and CRTs with a remote USRP, as a > useful hack for determining what TV channels people are watching nearby > (I know you can also listen for the local oscillator in the tuner, but > the tube probably leaks more energy, and gives you more information.
Ross Anderson and Markus Kuhn did some work on this. In fact, they designed a font that makes it hard to see the text on a computer screen when monitoring via Tempest emissions. And they have a great way of optical eavesdropping, based on watching a CRT's phosphor light vary over small increments of time (e.g. watching a wall that the CRT is illuminating). The USRP may be fast enough to capture such light from slow monitors, though the USB bottleneck gets in the way. See: http://www.cl.cam.ac.uk/Research/Security/tamper/ John _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
