LED Lights: Friend or Foe?

elfdump writes: "In an article (pdf) soon to be published in ACM Transactions on Information and Systems Security, security researchers have discovered that data transmitted through modems and routers can be remotely reconstructed from the equipment's LED status indicators. According to experiments, their light-to-information retrieval method is successful even when the light is captured 'at a considerable distance' from the source. If you want to prevent people from spying on your data, you may want to tape up those blinking LEDs!"

Comments

I call BS on this one...

[MentlFlos]

Ok, First off LED's as a status indicator just blink when there is activity. For example, a packet has been sent or received. Now how many variations can one packet have? I'm not even going to try to figure it out.

I can only think of one way this can happen. If someone wires up the LED's so that they are hooked directly to the transmit and receive wires so they do actually blink out the bits. Then one would need to send data slow enough so the LED (and receiver) can make out the individual pulses. In this respect, stupid=yes, impossible=no.

Or like usual, I could be just blowing smoke out my ass...