Re:Open source laser microphone picks up laptop keystrokes
by lrschaeffer on Tuesday August 13, 2024 @12:51PM
(#41237140)
Yeah, lots of different uses for a keyboard with wildly different frequency distributions. Writing an English letter != text chat in Spanish != data entry != league of legends. It's also not quite a substitution cipher due to modifiers (shift), toggles (caps lock), non-printable characters (escape, volume up/down), and deletion (backspace/delete).
It's an interesting problem you'd probably try to solve with Markov chains back in the day, but now you'd just throw machine learning at.
It would be trickier however if looking at raw keystrokes, as one has to consider several confounding factors:
* The caret can be moved both by keystrokes and mouse * You don't know what is being typed. If someone is typing people's names all day, or writing software then the analysis of letter/key frequency will be shifted
Not impossible, but makes the process harder.