Friday night topic: LEDs compromise data?
has created a minor sensation. It's a research paper that describes the possibility that emissions from LED indicator lights on communication devices like routers, switches, and modems might compromise the data being transmitted. Don't laugh, because it's very possible. The paper carefully explains how certain devices' LED lights can be read by optical sensors well enough to reconstruct the waveform of a data transmission. (You may have seen a story about this on CNN, but I encourage you to read the actual paper. It's quick, and it's worth reading.)
In fact, LEDs on some devices can bed read from across a room or even across the street. The authors also found that some encrytion devices have LEDs wired up to the input side, so the LEDs are transmitting unencrypted data. Also, at the end of the paper, the authors address some related issues, like a virus or trojan horse that might use keyboard LEDs as a covert transmission method. This method has been demonstrated to work at speeds up to 10Mbps.