FutureWatch - The Dark Art of Light Eavesdropping is Coming

Maite Brandt-Pearce, a professor in the Charles L. Brown Department of Electrical and Computer Engineering, and Mohammad Noshad, now a postdoctoral fellow in the Electrical Engineering Department at Harvard University, have devised a way of using light waves from light-emitting diode fixtures to carry signals to wireless devices at 300 megabits per second from each light. It’s like having a whole wi-fi system all to yourself; using light waves, there would be more network access points than with radio waves, so less sharing of the wireless network...

Their breakthrough means that data can be transmitted faster with light waves using no more energy than is already required to run the lights....

“You can use it any place that has lighting,” Brandt-Pearce said. “In a stadium, in a parking lot, or from vehicle to vehicle if using LED headlights and taillights.”

Like current wireless communications, encryption is necessary to keep data secure, but Brandt-Pearce noted that a secure network could be created in a room with no windows.

“It can’t be detected outside the room because the light waves stop when they hit something opaque, such as a wall,” she said. “That can keep communications secure from room to room.” (Generally speaking. However, a hair-like strand of fiber optic poking into the fixture from above the false ceiling should do the trick.)

And two separate networks in different rooms would not interfere with each other the way they do with present wi-fi networks.

She said devices with LED circuits in them can also communicate with each other. more more

Modulation of room lights for eavesdropping purposes is not new. The advent of ubiquitous LED lighting, however, will dramatically increase the effectiveness and ease of this tactic for eavesdropping... and the long-range wireless interception of computer data via optical means (even if it is encrypted).