cross-posted from: https://kbin.social/m/[email protected]/t/673723
Researchers in the UK claim to have translated the sound of laptop keystrokes into their corresponding letters with 95 percent accuracy in some cases.
That 95 percent figure was achieved with nothing but a nearby iPhone. Remote methods are just as dangerous: over Zoom, the accuracy of recorded keystrokes only dropped to 93 percent, while Skype calls were still 91.7 percent accurate.
In other words, this is a side channel attack with considerable accuracy, minimal technical requirements, and a ubiquitous data exfiltration point: Microphones, which are everywhere from our laptops, to our wrists, to the very rooms we work in.
If this is the same technique I’ve read about before, they need to start with a training set from the particular keyboard. You map the sounds of the keystrokes against the produced text.
I haven’t read about this approach yet, but my guess is that there’s enough of a difference between the sound of each key that they can tell with some percent accuracy which key was hit. It will probably be higher confidence for some than for others, and higher with a mechanical keyboard than one with butterfly switches. Combine that with the same kind of technology you use for autocomplete, and just keep iterating as more text is entered.