Snooping by listening to the keyboard

This is really clever. Ed Felten summarizes a paper (PDF) with a nifty security attack using the fact that keyboards make slightly different sounds when different keys are pressed.

From the paper:

We built a prototype that can bootstrap the recognizer from about 10 minutes of English text typing ... For English text, the language constraints can be applied resulting in a 90-96% accuracy rate for characters and a 75-90% accuracy rate for words.

There's some examples of the recovered text in the paper.

Remarkable and a little scary that, using nothing but a recording of typing and knowledge of patterns in the English language, someone can recover most of what was typed.

[via Bruce Schneier]