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Comment by tomatotomato37 | Hacker News Reader

Why is everyone more concerned over the ability of someone with too much time and laser modulation equipment telling their smart speaker to order 10 crates of hand sanitizer than the physics & possible new applications of influencing microphones via laser light?

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The technique of using light to transmit sound has been around for over half a century.. although it's more commonly used as a microphone rather than a speaker.

https://en.wikipedia.org/wiki/Laser_microphone

A microphone is just a reverse speaker. For example, if you plug your earbuds into an audio input port, you can use them as a microphone.

This is all relatively basic, just not obvious to most people.

I am not sure it is really as basic and obvious as you imply. The comparison between the "reversibility" of laser speakers/microphones and the reversibility of normal speakers/microphones is a bit off, in my opinion. For starters, laser microphones do not use the photoacoustic effect[1] that the device described relies upon. Whereas the reversibility of normal speakers/microphones is because both devices use the same physical process. That it's possible to build a microphone using lasers and to build a long-range sound generating device using a laser doesn't imply it's obvious (or even possible) to do so for any given audio production or recording technique. E.g., if I can generate audio using a flickering lightbulb, it is not clear that a flickering lightbulb can be used as a microphone.

[1]: https://en.wikipedia.org/wiki/Photoacoustic_effect

They also point out they can use this to bypass security and open "smart-locks".. this is slightly more concerning than just buying hand sanitizer.. I wouldn't be caught dead with one of these smart-lock devices, but I have friends who aren't so cautious.

I have owned several smart locks and every single one has required a secret passcode to actually unlock via a smart assistant. Working backwards, the real threat if they didn't do that is just someone shouting through the window.

I forget if it was this article or not but someone mentioned that a few of the smart locks that do have secret codes don't rate limit them, so, in theory, they could brute force a pin code or password.

I guess the idea is that they think nobody is going to sit there and shout pin codes until it unlocks?

I own a smart lock and my Google home device will only lock the door. You can't ask Google to unlock it.

I don't use a smart assistant, but I think some people use them with smart locks ("unlock the back door").

Alexa doesn't let you unlock, you can only check status and lock it.

Until a vulnerability is discovered.

How about telling their smart speaker to complete a task that might be connected to more sensitive things, like unlocking a door, opening a garage door?

Money is important to people.

Because it's about more than just buying stuff. Potentially you could say "Hey Siri, transfer all of my Monero coin to XYZ address".

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