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.
And rotate them. While I don’t plan to waste my energy, having hot swap sockets and swapping a few around should thwart the attack. You would have to do it frequently enough that relevant training data gets wasted before it’s useful. I’m pretty paranoid, but not that much.
I’ll just consider it good security hygiene to get a new keyboard often :)
Have you considered only re-doing the tinfoil wrapper every day? It should crackle differently every time.