Lasers used to hack Alexa??

[Anthony P]

I just sew a report on a local news channel about how a group of researchers used lasers to feed commands to alexa and siri devices. The beam was modulated through a laptop and able to send commands from 100+ yards away. The beam was striking the microphone.
For lack of better words... WTF?

 

[steve001]

I just sew a report on a local news channel about how a group of researchers used lasers to feed commands to alexa and siri devices. The beam was modulated through a laptop and able to send commands from 100+ yards away. The beam was striking the microphone.
For lack of better words... WTF?

See here. https://laserpointerforums.com/threads/hacking-with-a-laser.105807/

 

[Anthony P]

Thanks for the link, Steve. The real question I am still left with is how does light cause vibration in the diaphragm of microphone?

 

[steve001]

Thanks for the link, Steve. The real question I am still left with is how does light cause vibration in the diaphragm of microphone?

It's unknown even to the experts. Read the link in the article if you have not.

 

[paul1598419]

My daughter gave me one of the Echo devices that are the Alexa, but once I learned that they are listened to at all times by persons I put mine away as I don't want to allow others to listen to my conversations no matter how inconsequential.

 

[Anthony P]

I read the article and then researched MEM microphone. It keys off of varying capacitance when the diaphragm moves against a silicon wafer. Just wild speculation, but a photo voltaic effect induced by laser light.

 

[Arctos]

Thanks for the link, Steve. The real question I am still left with is how does light cause vibration in the diaphragm of microphone?

At around 20-30W RGB you can hear noise a laser makes on dark surfaces, it changes with the scan rate. It's very uncanny and ominous. Particularly with a lot of blue on corners of square patterns where the laser draws a few more points/dwells longer.
My theory is some sort of dielectric breakdown or interaction at that level caused by extreme photon flux and absorption causing a shockwave on the surface which couples to the air at a tiny scale. That energy has to go somewhere and not all of it will be heat..

At the 3kW pulse range with 25MHz and 550us pulse train lengths I've heard optical coatings dying too, it's a very distinctive crack sound and quite loud. Putting paper in the beam makes for vibrating sounds a little like putting a bottle in the spokes of your bicycle.

At even more power you can do it in mid air as it makes plasma. We are talking kW levels and you can make sounds and music. There was a military test for this but this one I found is only using a target to make the sound.

They have other videos too showing the laser doing other stuff.

Here is one example, Portal theme

 

[steve001]

YT channel Smarter Every Day.
A demonstration on various smart devices.