frizensami

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31.
by frizensami 5y ago
Thank you! While this work operates on ToF sensors that are already present in smartphones (e.g., Samsung S20+/Ultra), a Microsoft/Azure Kinect should also be a valid option because it has a depth camera as well. It has a higher r
32.
by frizensami 5y ago
This is actually one of the recommended methods if you have no other options. It's not particularly good otherwise because of the limited visibility cone of the hidden camera reflections. From experience, the flashlight often tends to
33.
by frizensami 5y ago
Thank you!
34.
by frizensami 5y ago
It's analyzing the camera feed in real time, so more like a video.
35.
by frizensami 5y ago
Yep, exactly.
36.
by frizensami 5y ago
We just used the OV2640 module itself ( https://www.aliexpress.com/i/4000036275403.html ) which is pretty small. While we didn't actually include a little battery and perhaps something like an ESP-32 to control it,
37.
by frizensami 5y ago
Unfortunately we can't steer the ToF beam, so the user has to move the phone around to multiple positions (a 2D grid of positions, basically). The app provides pretty clear guidance on where to move the phone to cover all possible spot
38.
by frizensami 5y ago
w.r.t the material, it seems to be possible, since ToF sensors operate in a narrow 850 nm band. However, I don't know if a coating can be made that also doesn't overlap with the visible light range since 850 nm is somewhat close t
39.
by frizensami 5y ago
Right, a few things would be very useful: - Increasing the resolution of ToF cameras (right now images are around 320 x 240) --> reflections from hidden cameras can then be more detailed, whereas now it's only 1 or 2 pixels each. -
40.
by frizensami 5y ago
Good question. We evaluated the "K18" hidden camera detector, and not the SpyFinder, but they use an identical principle.
41.
by frizensami 5y ago
That's a good point. I'm not sure how the removal of the IR filter will affect this work. I mentioned some prior work from the physics side [1] in another comment that explores the reflection characteristics in more detail. I don&
42.
by frizensami 5y ago
Great question about the angle actually. There's previous work by an applied physics group [1] that shows the detectable field-of-view from the camera is about 20 degrees. Our experiments also confirm that. We also think using the smar
43.
by frizensami 5y ago
Yep, there are a pretty decent number of smartphones with it, and I think the trend is moving in the right direction (iPhone 12 Pro had it and Apple included it in the iPhone 13 Pro too).
44.
by frizensami 5y ago
Sadly no project-specific page yet, but I'll definitely update on my page at https://sriramsami.com/research/ (I think there's an RSS feed?) when it's active.
45.
by frizensami 5y ago
Yeah, that's fair. If someone really wanted to do this though, they could also just use existing products like this one: https://www.amazon.com/Worldoor-Multi-Detector-Full-Range-Al... .
46.
by frizensami 5y ago
Yes, we do! There are a couple of user-facing annoyances at the moment, one of which I mentioned in another comment (hacks to align the color and ToF images). Hopefully these API limitations are removed soon, or we find better workarounds.
47.
by frizensami 5y ago
Author here, sorry, I didn't post this (but it is the paper's title). Hopefully it gets corrected.
48.
by frizensami 5y ago
Hey! Author of the work here. We just finished presenting this at a conference yesterday, so we're working on open-sourcing the code now with some feedback from the community. It's got some warts because of API limitations (no way
49.
by frizensami 5y ago
Hey! Sriram here, author of this work. I'd be glad to answer any questions. There's also a short talk I gave about this here ( https://www.youtube.com/watch?v=t4Txdhlji4k ) if that's helpful!
50.
by frizensami 6y ago
I believe there is previous work that re-wires / re-purposes speakers to be used as microphones. However, my understanding is that this requires the hardware itself to be modified.
51.
by frizensami 6y ago
Thank you! For the Xiaomi Roborock S5, the plastic housing around the LIDAR makes it hard to see if it's rotating when you're standing above it. If you bend down and look at it side-on, you can tell whether it's rotating or n
52.
by frizensami 6y ago
Hey! Actually, this was investigated previously by Dennis Giese here ( https://recon.cx/2018/brussels/resources/slides/RECON-BRX-20... ). He also has a number of related talks ( https://dontvacuu
53.
by frizensami 6y ago
Right, good question. Anything that is very rigid and heavy doesn't vibrate enough when we play sound near it. I would say it's more about the thickness and weight of the target object than the material itself. For example, a very
54.
by frizensami 6y ago
Hi, first author of the paper here. We also consider this as part of the increasing arsenal of smart-home attacks, which can be opportunistic and long-term. Also given that it's an offline attack, as signal processing / machine le
55.
by frizensami 6y ago
Yes, this is really cool project that we used in the paper as well!
56.
by frizensami 6y ago
Hello all, I'm Sriram, the first author of this paper. We were inspired by the idea of laser microphones as an audio eavesdropping vector, and tried to find a way to use LIDARs similarly, even though they're not designed for this