Power Outlets Reveal What You Type

Researchers reveal that snoopers can detect what you type on your computer through the power outlet.

It seems absolutely unlikely, but security researchers have revealed that bad shielding on some keyboard cables mean that snoopers can discover what you’re typing – via the power outlet.

So far leak has been detected from a distance of 15 meters, but with further refinement that distance could be greatly increased.

In a paper describing their work, Andrea Barisani and Daniele Bianco, of security firm Inverse Path wrote:

"Our goal is to show that information leaks in the most unexpected ways and can be retrieved."

Their focus was on the cables that connect PS/2 keyboards to computers, according to the BBC. The six wires in the cable are poorly shielded, so when a key is pressed, information leaks into the ground wire within the cable, which eventually connects to the ground in the power outlet.

Data travels along the cable one bit at a time, so, using a digital oscilloscope, data about the voltage changes could be gathered, with non-keyboard functions filtered out.

"The PS/2 signal square wave is preserved with good quality… and can be decoded back to the original keystroke information."

The duo will be demonstrating their attack at the Black Hat Conference in Las Vegas during the last week of this month.