On 8/25/19, jim bell <jdb10987@yahoo.com> wrote:
https://www.newsbreakapp.com/n/0MbloCip?s=a3&pd=02h1yVjC
Hackers can tell what people are typing just by listening through a smartphone's microphone
Peter Wright's 1970's book, Spycatcher, described an early, primitive version of this technology.
I am curious how this is currently done. And in the case of modern, computer keyboards, what noises is the system looking at? The noises the keys themselves might be fairly similar; maybe it is listening for the difference in timing that a human-generated keystroke would exhibit.
Search for the series of audio keyboard attack whitepapers that were making their rounds a decade or so ago. (See also TSCM-L, TEMPEST.) Every key sounds physically different, plus the unique function of the person pressing, that key characterization paired with character frequency dictionary analysis, finger length keytime distance, interpress brain timings during language formation, Markov windows, etc. More characters over time, more accuracy. Especially with chosen plaintext, oppurtunity sampling the keyboard upon casual visit to the room, etc.
At first thought, I figure that using Tempest-type (RF emission) techniques on keyboards would be more plausible: The encoder chip which scans keys will likely have precise timings. And it should be possible to program a different encoder chip with intentional emissions of identifiable signals, which can be listened to from a relatively long distance away, tens or hundreds of feet.
Areas of defense are on the market meant to buffer, reclock, encrypt, jam, insulate, out of band, etc... in keyboard hardware, OS software, touch glass, ocular input goggles, and free basic environmental blinding cover... heavy metal music... https://www.youtube.com/results?search_query=anthrax+noise If your adversaries have to risk exposing themselves by getting up close and physical, either you're doing something right, or horribly wrong to be located in the first place, or it's just your way of banging hot Russian spies :) https://duckduckgo.com/?iax=images&ia=images&q=sexy+russian+spies infohash:3A3BC4904B9B562809547FF41ABFE285EB6E4D3C https://www.youtube.com/watch?v=mUqeBMP8nEg