Scientists Use WiFi to See Through People's Walls

gedaliyah@lemmy.world to Technology@lemmy.world – 458 points – Scientists Can Now Use WiFi to See Through People's Walls
popularmechanics.com

“We developed a deep neural network that maps the phase and amplitude of WiFi signals to UV coordinates within 24 human regions. The results of the study reveal that our model can estimate the dense pose of multiple subjects, with comparable performance to image-based approaches, by utilizing WiFi signals as the only input.”

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Absolutely ludicrous to paint this development as anything but the wet dream of both a burglar and a police state.

Also VR nerds. Current tracking is either based on the headset, so you can't move your arms unless the headset can see them, or your arms have to be seen by lighthouses, or you rely purely on gyroscope and accelerometers for tracking, which tend to drift. So either you have blind spots, have to deal with occlusion, or will slowly drift and have to recalibrate periodically. Wifi-based tracking seems like a neat idea tbh.

Edit: considering wifi is just photons that aren't wiggling fast enough for us to see, I'd be surprised if the government doesn't already have this technology behind closed doors.

For VR I don’t see why we wouldn’t use a variety of other technologies before we ever use WiFi. The main issue with the WiFi thing is going to be polling rates and interference (which limits polling rates). They’re also using a neural net here which requires both processing power and time so there’s latency far beyond VR uses. That’s without talking about tracking that would be needed for higher spatial resolution which this also doesn’t have currently. So it’s not impossible to use this, just not currently practical or even close.

The real solve to that stuff is just an improvement on existing tech or maybe Lidar. With the progress that has been made on the Quest with hand tracking, I’d bet their next goal is body and face tracking so you’ll see this soon.

As for the government having this, I doubt they really need to have it this specific to track poses or body parts. If you have a cell phone on you, they likely know exactly where you’re at in a room. If you don’t, I’m betting they have access to other important data. Motion detection, number of people, room shape and some contents, interference sources.

Home automation nerds would also cream their pants if they could get their hands on this. Imagine you could use your existing wifi router to detect presence in your home. Say goodbye to shitty IR sensors that forget about your existence within 3 seconds, no more finicky radar modules that are either too sensitive or not nearly sensitive enough.

I literally just have my machine ping my phone every ten seconds. Surprisingly effective presence detection.

How would one go about setting this up? Because that sounds really cool for home automation.

It's a very crude way of detecting presence for a variety of reasons, and likely won't be as useful as you imagine.

The biggest problem is how modern smartphones handle networking when they're locked. They enter a power saving state where they don't respond to all pings, or they respond late enough that the pinger decides the device is just not there. Of course there are ways around it, but those are things you need to do explicitly so it won't work on all devices until you've taken the time to set it up.

And since it detects a mobile device's existence in the local wireless network rather than the actual presence of a human being, it's not very flexible at all. What if you want to detect the presence of a guest? Are you gonna make sure they're on your network with their devices set up to properly respond to pings? What if you forgot to turn on your phone's wifi after turning it off?

I mean it does work once you've set it up, but do expect it to have a very limited scope in what you can and cannot do with it.

There is this Home Assistant integration which I remember getting working. I haven't used Home Assistant in a while though, so I can't be a good resource if you need any help.

Honestly, I wouldn’t be at all shocked if uncle sam and his favourite three letter agencies have been playing around with this tech for years.

I mean you can look through my walls if you want, but don't come crying to me if you don't like what you see.

(I'm painting fantasy miniatures. They're for a friend.)

Same, but the fantasy miniatures are sex toys and the paint is my butt.

A good hobby is a wonderful thing, indeed!

"we threw a deep neural network at the wall to see if it sticks"

Lets hope the government is transparent about its use of this technology.

All the information you want to know is available at: REDACTED

Article is from a year ago. Government tends to be ahead of the curve. As an uninformed guess, they have been using it in high value situations for 4+ years.

(Dear FBI, the above is a guess based on public information. I don't know shit.)

Government tends to be ahead of the curve.

I dunno what world you're living in, but I live in a world where police still do nearly all their work with pencil and paper and if you want to talk to a police officer, no you can't talk to them on the phone or send an email. You'll have to have a meeting face to face.

Actually, police do tend to be reasonably ahead when technology is invasive. I've heard many stories about them seeing through walls with other technology. They also tend to like face-tracking, which is pretty advanced. They just are really far behind on technology that could be used to hold them accountable.

Which leads to the obvious question: how long has the military been able to do this?

https://en.wikipedia.org/wiki/Tempest_(codename)

Here's the summary for the wikipedia article you mentioned in your comment:

TEMPEST is a U. S. National Security Agency specification and a NATO certification referring to spying on information systems through leaking emanations, including unintentional radio or electrical signals, sounds, and vibrations. TEMPEST covers both methods to spy upon others and how to shield equipment against such spying. The protection efforts are also known as emission security (EMSEC), which is a subset of communications security (COMSEC).

^to^ ^opt^ ^out^^,^ ^pm^ ^me^ ^'optout'.^ ^article^ ^|^ ^about^

Umm, article from Jan 19, 2023. I remember seeing it then. Is there anything new on this?

The paper: [Submitted on 31 Dec 2022] - I'm not sure if it's out of prepublication yet.
DensePose From WiFi - https://arxiv.org/abs/2301.00250

Here's another tidbit from July 2, 2023 DensePose from WiFi - See through the walls. - https://www.linkedin.com/pulse/densepose-from-wifi-see-through-walls-alejandro-fern%C3%A1ndez

And another from July 25, 2023 Revolutionary Applications of DensePose From WiFi: Enhancing Corporate Security and Empowering Military Tactical Teams - https://www.linkedin.com/pulse/revolutionary-applications-densepose-from-wifi-enhancing-zack-hamm

Here's a video summary of the paper I thought did a good job too from two minute papers.

https://youtu.be/kBFMsY5ZP0o

Thank you for the vid link, got a new channel subscribed now. Great starting point to show people and dive down the rabbit hole with.

Wasn't this the plot point of The Dark Knight?

And everyone thinks Batman was the good guy.

starts putting paint on face

The whole point of that scene was that he was overstepping the line.

But then cops wear Punisher logos and Republicans play Born in the USA at election rallies, so who knows how the masses interpreted it...

That's just another example of why Batman was literally evil.

If I didn't have a reason for why Ethernet is superior, I have one now!

... that you CANT see through walls? Seems like a downgrade to me...

Hey, I don't want IRL wallhacks 😭

I am going to repeat myself forever it seems. We got it wrong when we decided that you only have privacy when someone can't physically see what you are up to. Nothing else is treated this way. You are not allowed to drive as fast as your car can physically move. You are not allowed to go into anything locked as long as you are able to pick it. You are not allowed to steal whatever you want as long as no one tackles you for it. And yet somehow some way it became understood that merely because someone can get a photo of you they have the legal right to do so.

As if access to better technology means you should follow less moral rules vs the opposite. Someone with a junk camera of the 80s can do far less perving compared to the new cameras+drones out there.

it became understood that merely because someone can get a photo of you they have the legal right to do so.

What jurisdiction is this true? There are certainly times that there is an expectation of privacy and getting a photo of you would be illegal. Easy example: and owner of a store can't photo you in the dressing room, the even tho they could put a camera in there. It's the same thing here, there is an expectation of privacy in your home (or for many enclosed and private spaces), so this kind of "picture" would likely already be a violation.

Just about all of them where the government is spying on their residents. Unless you think it's alright if the government does it?

The poster made the claim:

it became understood that merely because someone can get a photo of you they have the legal right to do so.

And now you're talking about the government spying. Total non sequitur that has nothing to do with what I was discussing.

The posters claim goes a bit further than just "can get a photo of you". The poster originally mentions (and it's integral to the point) that privacy shouldn't be predicated on the idea that so long as you are behind closed doors (ie not in view) you have the expectation of privacy. You deliberately narrowed the scope. But please understand that technically my car and the contents thereof are covered by a right to privacy. To search my car lawfully in the US you'd require a warrant. Doesn't matter if my car is parked on the street. But you could lawfully take a photo of me in that car pretty much anywhere in "public" and that would also be considered lawful. So, what exactly is the demarcation? Where is the line drawn and doesn't that seem rather arbitrary?

The context of the poster you responded to's point is that the government decides and makes a line between what is private and what isn't. And that's further defined and enforced by laws. When you take into account the number of tools governments the world over have developed to spy on their citizens and just how many of those are then made available to or leaked to the public, and further that some of them being used in public are perfectly legal that poster has a point. We did not draw the line in the sand the right way.

To search my car lawfully in the US you’d require a warrant. Doesn’t matter if my car is parked on the street. But you could lawfully take a photo of me in that car pretty much anywhere in “public” and that would also be considered lawful.

The poster said nothing about the state. They were talking about privacy. They gave a long list of things that we aren't allowed to do even if we are "able" to do them, and then made the false claim that we are allowed to take pictures "just because we can." Maybe they have beliefs about the line being in the wrong place for other things, but this submission is about a type of picture, and the poster specifically mentioned taking pictures. So me talking about picture makes perfect sense, bringing in the state searching your car makes next to zero sense.

The context of the poster you responded to’s point is that the government decides and makes a line between what is private and what isn’t.

The poster said absolutely zero about the state. None. Zilch. Zip. When you accused me of narrowing the scope, you were actually projecting your expansion of the scope.

But make no mistake about it, if a cop walks by your car and sees a dead body in the back seat, they don't need to get a warrant to search your car...because there is no expectation of privacy...which is, of course, actually what we are talking about.

Who determines privacy? Who enacts the laws? How is privacy enforced? What happens when you report someone for invasion of privacy? I don't understand how this issue can have context without mention of the state.

And we are allowed to take pictures just because we can. If I take your picture in public? Just about nothing you can do about it unless it breaches some other law (like what you mentioned with filming in bathrooms). There are specific things I can't do with that photo, for instance if that person happens to be famous they may have a right to publicity and their image etc. But they don't have rights to copyright or the like. Could I post their photo in a random online forum claiming they have done something illegal? Nope? Can I blackmail them? Nope. But I can absolutely use their photo in a copyrighted way for art or even business.

I don’t understand how this issue can have context without mention of the state.

Sure, which is why I challenged them over jurisdiction on their false claim that you could take a picture wherever you want. You even seem to agree with me that that is not the case.

Could I post their photo in a random online forum claiming they have done something illegal? Nope?

Because this is libel. You are allowed to say whatever you want, "unless it breaches some other law." Just like your limits on what pictures you can take are not "just because you can" but "unless it breaches some other law."

It all comes down to an expectation of privacy. You have none in a public space as what you are doing everyone else can see.

And the implication of their initial point, in the context of the submission, is that this type of "photography" would be allowed because "you can" and I argue that this would already be protected under current law that there is an expectation of privacy behind in your home. Like in many (it not all?) I can't take a picture of you in your home through a window even if I can see you from a public space, because of the expectation of privacy.

That's exactly what I mean though. It is libel. It's not privacy law. That was the point of saying other laws. But I'm not sure that is what they OG meant when they said you could do whatever you want. I took that to mean an implication that there's a lot of lawful things you can do with someone's picture that you absolutely can gain legally, and should be a breach of their privacy under op's defined parameters.

Just about all of them where the government is spying on their residents. Unless you think it’s alright if the government does it?

This is your first response to me. Can you explain to me how I could have possible figured out what you just said from your initial post? You've moved so far from your first post, without at any point admitting at any point that you were wrong or maybe misinterpreted something.

Stop trying to be right and start trying to figure out what's right. You are clearly smart enough to do so.

Duh? I don't think anyone with the right field of study thought this wasn't possible. It just doesn't have good use cases.

I'm an EE, and I have serious doubt about this actually working nearly as good as they are putting it. This sort of stuff is hard, even with purpose built radar systems. I'm working with angle estimation in Multipath environments, and that shit fucks your signals up. This may work it you have extremely precisely characterised the target room and walls, and a ton of stuff around it, and then don't change anything but the motion of the people. But that's not practical.

It's Popular Mechanics, of course it doesn't work as well as they say it does. But the theory has been around a long time.

You are correct, at best this requires some a priori knowledge of the room. You can kind of do basic motion detection blindly though. They are just measuring the channel response via the 802.11 preambles, so for basic presence detection knowing that the channel response is changing is enough.

I was under the impression these experiments required a pre mapped room with EM readings. I don't think they can watch you like if it was an X-ray but I'd believe it if they could track blobs of moving mass.

Full body vr tracking without sensors?

The human presence sensors based on this are already on the consumer market, we just need to dial up the sensitivity.

There are already smart light bulbs you can buy off the shelf that use radio signals to see when somebody is in the room. Then it can turn on the lights automatically, without a camera or infrared sensor in the area.

Henceforth, the building code shall make mandatory that every room be perfectly grounded Faraday cages (/s).

Still, imagine lethal drones integrated with that technology (of course, they already have infrared, maybe even some adequate wavelength of X-rays).

Nevertheless, pretty cool to see how far we can take preexisting technology with the help of some deep learning layers.

Here's what they're putting in the goggles that Infantrymen wear now.

I don't care to guess what the drones are packing.

What we know about drones is that they have cameras that can discern individuals from 10 km altitude.

What we suspect is that US has Hubble-sized spy satellites that can do almost the same. There were a lot of classified military STS missions.

What is theoretically possible is that US drones and spy sats can function as very large arrays (we do this with astronomical telescopes already) to dramatically increase spatial resolution.

I'd believe it. When I was in the infantry 20 years ago we could see you 3km away with the optics mounted on our machineguns. And several kilometers with cameras mounted on towers. I don't know how far they went but it was at least 5km because we were directing mortar fire with them and that's about the range of the mortar system we were using.

Oh I wonder if that's how the Pic was taken that trump tweeted out of that rocket launch site, people didn't think it was physically possible for a satellite to have that resolution

It all comes down to the size of the mirror/lense—the bigger, the better. Up to a point. The biggest problem is air currents and different air densities refracting light and distorting the image. That's what these laser beams are for on photos taken of astronomical observatories—they give reference light spot that can be used to calibrate adaptive optics to current atmospheric conditions reducing distortion.

Based on the cell phone reception in my house, I already suspect it's a Faraday cage.

near future building insulation will include enhanced EM spectrum insulation, to prevent or distort leakage into the environment

Get Lucius Fox on the horn.

Add a ! at the start to embed images.

Add a ! at the start to embed images.

Yep, I always do that, but my understanding is that functionality is broken on kbin, or otherwise isn't working as expected.

Sadly lots of features are not working on kbin, or less specifically various services in the fediverse. One example is spoilers. Last I checked there is no consistent spoiler syntax that works across the fediverse, and so spoilers are dangerous territory. Hell, even some apps don't handle spoilers appropriately just for Lemmy.

Wait, I thought this was a crackpot conspiracy thing?

Nope, that's what they want you to think. Just wait a few decades and we'll find out tin foil hats will actually have some use

did you never read that MIT guy's research on the tin foil hats?

Because I'm supposed to trust MIT as if it's never gotten CIA funding ( ͡° ͜ʖ ͡°)

This article is a year old. Do we have posting standards in here?

The tech is even far older than the article. I remember seeing this being demo'd at least a decade ago. Though, it looks like the fidelity has improved significantly from the early proof-of-concept videos that were floating around for a while.

Years ago there was a journal on gait recognition through home WiFi.

I wonder if it's real time? If yes then this is good for VR.

Interesting! It could theoretically act like a Kinect if it were advanced enough, and you wouldn't need any additional hardware.

This has a bunch of additional hardware, much more complex than the Kinect camera

The reason this is good for privacy is because we don't need a new smart device to send other (like video) data away for heavy processing in the cloud.

We might instead be able to just update wifi routers to create local functionality.

Then it will depend on the router and the user configuration what actually happens with that data.

The user can have full local control…. Except neighbours wifi could be spying and so could someone with a wifi device in a car. But if putting a faraday cage around peoples exterior walls (combined with an underground physical cable to an internal extender for phone and roaming while insid) becomes a thing then it looks it could be a great system theoretically.

Gotta wait to see how it might look in practice though.

I heard that they can analyze window glass to get audio recordings because as a slow moving liquid, vibrations in the air leave an imprint on the glass.

Sounds like Fringe Science to me, honestly

The "glass is a liquid" thing is a myth. The reason why old windows tended to be thicker at the bottom (which is usually the cited reason for this myth) is because windowpane making techniques weren't very good and so they would always have one thicker side. The builders would naturally install the pane with that side on the bottom because it was more stable. Glass doesn't "flow" over time, it's a solid crystalline amorphous material.

You had it until the end. Glass has an amorphous structure, not crystalline, but is still very much a solid.

They bounce a laser off the glass and can hear what's happening in the room by capturing the vibrations of the glass. I seem to remember the US embassy was caught spying on the Canadian Prime Minister using this technique.

Yep I have read that sensitive buildings are now built with a hallway ringing the building and offices further inside, so the rooms where classified things are discussed don't have windows accessible by outside lasers.

Yes that's possible and it has some years but there's some conditions. The glass needs to have a sticker onto it for the trick AFAIK is to reflect a laser or infrared light onto it and track the less than milimétric vibrations of it and depending on where is the sticker and how big is the window it affects the quality of the recording. Given this wifi trick I think it would have to do with signals not passing through water clearly or some thing on the likes and more over it should need some specific equipment to pull out the trick, I don't imagine you could just hack a router and patch surveillance in the firmware.

Damn, hackers do be eating good in the future 👀