Hacker News Reader

Comment by sp332 | Hacker News Reader

This is a cool attack, but I'm not sure where you got "$14" from. The laser pointers were $18 for a pack of 3, but you need a separate laser driver like the $300 one the authors used, and probably an audio amplifier as well.

There are some videos of the attack at https://lightcommands.com/

View on HN

Exactly. Title says "$14" and then show this as the setup: https://i.imgur.com/SYUSIDs.png

"Google Assistant can be hijacked by a $2 pack of screws!"

If you scroll further down, they show a significantly cheaper setup.

So your typical Reddit/Hacker News new computer build.

"$300 for the whole thing. (Note: This doesn't include the GPU, motherboard, case, or monitor that I already had prior to building.)"

Agree, title should be more like "Light Commands: Laser-Based Audio Injection Attacks on Voice-Controllable Systems"

Particularly as this isn't exclusive to smart assistants. They found the same could be used against phones and tablets (as slightly higher power due to the lower sensitivity of the microphones).

Yes, but it's targeting the aforementioned software regardless of device. (Not that the HN title isn't terrible, I agree with thsowers on using the title from the actual paper.)

I think it's extendable, like adding extra voices to a phone call.

Stipulating that $14 might be off by as much as two orders of magnitude, cost remains an insignificant barrier for any adversary with access to a credit card.

We changed the title from "Siri, Google Assistant, and Amazon Alexa can be hijacked with $14 laser pointer".

Submitters: please don't editorialize like that. It breaks the site guidelines: https://news.ycombinator.com/newsguidelines.html

I foresee a market for decorative chotskies with open centers that sit over the mic to prevent these peripheral attacks.

Clickbait PDF

To be fair, the PDF's title is different, "Light Commands: Laser-Based Audio Injection Attacks on Voice-Controllable Systems".

Maybe we should change this submission's title to the PDF's title.

Modulating a laser at audio frequencies is pretty trivial.

You can probably inject the signal straight from the headphone output of a smartphone into the right pad in the laser pointer with a decoupling resistor and inline capacitor.

...if you don't care about audio quality and longevity of the laser.

http://www.yak.net/fqa/229.html

Reply on news.ycombinator.com