For the technique to work reliably, words must be three letters or more. Working with a 58,000 word dictionary, the researchers found their word recovery rate was as high as 80 percent.

Should you start being paranoid when a colleague places their by your keyboard? Not really. "The likelihood of someone falling victim to an attack like this right now is pretty low,"Traynor says. "This was really hard to do. But could people do it if they really wanted to? We think yes."

Carter, Traynor, Verma, and Marquardt will present their findings in a paper entitled "(sp)iPhone: Decoding Vibrations From Nearby Keyboards Using Mobile Phone Accelerometers" on Thursday at the in Chicago.

Follow freelance technology writer and on Twitter.