[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] "Tempest" for LCD displays?
From: |
John Gilmore |
Subject: |
Re: [Discuss-gnuradio] "Tempest" for LCD displays? |
Date: |
Sun, 19 Jun 2005 23:48:16 -0700 |
> 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