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Comment by 0cf8612b2e1e | Hacker News Reader

Wish they had waited to publish for when he had posted the plans. I am also curious to see the BOM, because in the article it said he spent thousands on equipment, so I hope that was V1, and a working model can be had for a more modest budget.

Supposedly the White House uses vibrating windows to avoid this class of attacks.

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I'm also super excited to see more on this, it's been living rent free in my head for a long time. I played around with keypress extraction from sound recordings a couple decades ago in college, and it was remarkably straightforward to extract keypresses based on sound signals, even with zero training - based on the time between keypresses and the unique signature of space/return/backspace you can build a predictor pretty quickly. We never made it to the "bounce a pair of lasers off two window panes a known distance apart and triangulate everyone's keyboard", but it was one of those things that's definitely doable with enough time and brains.

I remember making a demo in 6th or 7th grade of console login dialog and disclosing password asking friends to log in.. they couldn't, because during typing my program would analyze time between pressing different keys.. I don't remember if I hard coded it or it was trained first... But yeah, essentially it was checking not just the password, but also signature of it..

I've worked in a few places that use vibrating windows to defeat parabolic directional microphones; they've been an imoportant counter espionage measure for at least 25 years - probably a lot longer!

I'm assuming this cannot be either a stable signal or a well known source like a local Radio station because then you could "subtract" the noise and .. well get the in-room sounds just like you used to.

Or it has sufficient energy to make any transmission effects through vibration useless because broad-spectrum the glass is shaking to shakira too much anyway.

The main countermeasure is just curtains with a bit of weight to them.

Human element is going to thwart your countermeasure when they want to let in some light.

Weighted curtains don't really help with sound dampening that much unless it's somewhat air tight. I shopped around a bit for window sound dampening products, them need to form seal around the window hole.

The word is "damping," not "dampening."

(I am willing to die on this hill.)

oh haha my bad, not that I can use ESL as an excuse anymore since I effectively use it more than my native.

Do you have a source for the vibrating windows? That is super interesting.

Hope that frequency varies at random for the Whitehouse.

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