Laser Sniffing Captures Typed Keystrokes From 50-100 Feet

Death Metal writes "Chief Security Engineer Andrea Barisani and hardware hacker Daniele Bianco used handmade laser microphone device and a photo diode to measure the vibrations, software for analyzing the spectrograms of frequencies from different keystrokes, as well as technology to apply the data to a dictionary to try to guess the words. They used a technique called dynamic time warping that's typically used for speech recognition applications, to measure the similarity of signals. Line-of-sight on the laptop is needed, but it works through a glass window, they said. Using an infrared laser would prevent a victim from knowing they were being spied on." (This is the same team that was able to pick up the electromagnetic signals emitted by PS/2 keyboards.)

Re:on the contrary: !Easy to dectect

[DMUTPeregrine]

Also, the point is to point the laser at the window and have it reflect. By measuring changes in the angle of reflection you can reconstruct sound hitting the inside of the window. Double-pane glass with a vacuum between the panes removes this attack vector.