At the recent DefCon conference in Las Vegas, hacker Sami Kamkar demonstrated a concerning new technique involving the use of an infrared laser for espionage. Kamkar showed how this method can be used to read the keystrokes on a computer and to record sounds in a room, all from outside through a window. The technique is based on capturing vibrations that occur when keys are pressed or sounds are made, which can then be deciphered.
The process involves directing the laser towards a reflecting surface on the computer, such as the metal case or logo on an Apple device, which reflects light effectively. The laser picks up the tiny vibrations created by the user’s actions and converts them into data that can be used to reconstruct the text that was entered. Kamkar even managed to capture music playing in the room in some instances, with the reconstructed text only containing a few errors.
In addition to keystroke surveillance, Kamkar also enhanced a laser microphone that can record sounds in a room by reflecting the laser beam off a window. This microphone detects the vibrations in the glass caused by sound waves and transforms them back into audible sound. While the quality of the sound can be affected by double-glazed windows, it still can produce clear enough audio in some cases.