DensePose from WiFi | Hacker News Reader

DensePose from WiFi

arxiv.org

176 pointsdeverton44 comments

IEEE 802.11bf aims to standardize through-wall motion sensing for Wi-Fi 7 in 2024, https://www.originwirelessai.com/insights/what-is-the-802-11... & https://www.originwirelessai.com/insights/origins-next-chapt.... It can be done today with custom firmware on low-cost WiFi devices. Over the past decade, hundreds of Wi-Fi sensing papers have been published, for different categories of motion.

> capture tiny, vital movements of human breathing, even when people are not in the line-of-sight of a device ... whole home coverage to detect falls, breathing rates, abnormal behaviors ... Internet Service Providers (ISPs), Security, Health & Wellness, Automotive, and IoT

The images in the DensePose paper are helpful: https://twitter.com/aibreakfast/status/1613550599144091650

Prior HN threads on Wi-Fi 7 Sensing: https://news.ycombinator.com/item?id=33758434

Counter-measures: https://news.ycombinator.com/item?id=27121918#27133079

Sign me up for the security system. This seems like a total game changer if it's possible to do real human detection and tracking in a secure location.

2012, https://www.popsci.com/technology/article/2012-07/seeing-thr...

> The U.K. Ministry of Defence has funded a study to determine whether it could be used to scan buildings during urban warfare. With improvements, Woodbridge says, the device could become sensitive enough to pick up on subtle motions the ribcage makes during breathing, which would allow the radar to detect people who are standing or sitting still.

Enter some weird cyber-defense suit which masks bodily movements when you sit still...

Sounds more like a job for just plain old RF jamming.

I have a weirder utility for it: occupancy sensing in rooms.

If it can detect breathing of humans reliably, then it solves a huge problem in having home automation with automatic lighting - particularly in bathrooms. I've never had a decent bathroom occupancy sensor (they all end up wanting to detect fairly large motions) - the obvious solution is AI with a camera but for obvious reasons no, but if a couple of base stations can localize person positions to rooms in the house (and provide other services) then that kind of solves the whole issue!

Is there anything wrong with mechanical switches, beside the apparent (though negligible for me) improvement in comfort?

I grew up with a father who was obsessed with the idea that we were wasting electricity by accidentally leaving the lights on sometimes. As a result he's spent probably thousands in attempted energy saving devices which have all not worked and definitely would never save enough compared to the cost of them.

Which is why I think about these things despite this seemingly obvious solution.

And the fact that the guest bathroom when I visit his house still has no light switch but does have a cheap motion sensor which is annoying as hell.

There are a number of mmWave occupancy sensors that are more than capable of this. The biggest issue is the delay introduced in most smart home contexts by Zigbee and the hubs. Matter/Thread should help here.

Existing options: https://smarthomescene.com/reviews/best-mmwave-human-presenc...

The Aqara FP2 should be out in Q2 with Matter support and be a nice upgrade. It can segment a room into multiple spaces and detect 5 people.

"Please drink verification can to continue."

From the abstract: "This paves the way for low-cost, broadly accessible, and privacy-preserving algorithms for human sensing."

How much do we have to wait for the follow up paper: "Human identification through wifi signals" and then the patent for "Wifi as an identity tracking source for advertisement in public spaces"

Technology advances make me sad those days...

> How much do we have to wait for the follow up paper

Early work from ~2010, https://dhalperi.github.io/linux-80211n-csitool/ & https://groups.csail.mit.edu/netmit/sFFT/soda_paper.pdf & https://dspace.mit.edu/handle/1721.1/103715

1000+ papers, add your surveillance keyword and 'Search within citing articles': https://scholar.google.com/scholar?cites=4354757827101869878

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

> In 2012, her work on Sparse Fourier Transforms was chosen as one of the top 10 breakthroughs of the year by Technology Review ... In 2014, on the celebration of Project Mac's 50th anniversary, her work on X-ray vision was chosen as one of the "50 ways that MIT has transformed computer science."

Sample paper topic keywords, http://web.archive.org/web/20210620035520/http://dhalperi.gi...

  human-to-human interaction recognition
  device-free human activity recognition
  occupant activity recognition in smart offices
  emotion sensing via wireless channel data
  CSI learning for gait biometric sensing
  sleep monitoring from afar 
  human breath status via commodity wifi
  device-free crowd sensing

Measuring sleep position with wireless signals https://people.csail.mit.edu/scyue/projects/bodycompass/

You can distinguish people by their gait, so it may be plausible that measurements of gross movements can pick a person out.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3925574/

Wouldn't gait tracking be the obvious next step?

I was thinking the same thing

> Human identification through wifi signals

It is already easy to track anyone who owns a smartphone.

Probe requests broadcast the MAC address: https://medium.com/@brannondorsey/wi-fi-is-broken-3f6054210f...

Wi-Fi Sensing can potentially enable identification of humans carrying _no_ devices.

> Probe requests broadcast the MAC address: https://medium.com/@brannondorsey/wi-fi-is-broken-3f6054210f...

Summary is good:

> Wi-Fi is fucked, everything is broken, Donald J. Trump is president, and the earth is dying. Ok, taking a step back, you might be wondering what you can do to protect yourself. The solution is not without flaws; turn your Wi-Fi off when you aren’t connected to a known network. Doing so will prevent your device from leaking your network names and device fingerprint to the open world. The solution is awkward, easy to forget, and sub-par. But its what we’ve got.

That's why many vendors randomize MAC addresses, at least where and when possible.

Cmon, use your imagination, It’s worse than that. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6513191/

I'm not sure "Privacy preserving" is the phrase that springs to mind with this tech.

> This paves the way for low-cost, broadly accessible, and privacy-preserving algorithms for human sensing.

Just because this surveillance tech avoids photons with energies accessible to human photoreceptors doesn’t mean it preserves privacy.

Take a look at Figure 10, mind blowing.

This tech will make it into every device with an RF receiver. Your TV, phone, router, computer, tablet, fridge, lightbulb will know your pulse and waste size at all locations in your house.

I think you meant waist size, but the typo is even more privacy invasive.

My bad, I meant waste volume.

Plus keyboard-entered passwords, thanks to mmWave radar being added to the Wi-Fi spec, https://news.ycombinator.com/item?id=30172647

This could be a boon for thieves, allowing them to scan for empty houses at night, so they know which ones can be more safely targeted.

It can also serve as a replacement for IR sensors in homes and keep thieves at bay

Who do you think will be faster in adopting the technology—burglars or homeowners?

Moreover, thieves are likely to use custom-built RF occupancy detection devices, while the vast majority of homeowners will buy an off-the-shelf product that will either sell their data to advertisers (a la "smart" televisions), require a subscription service, or both.

When we have near-human level deep learning models for things humans can do, what does this level of performance look like when applied to things we can’t do at all? This is a nice example of this.

The side-channel attacks are coming from inside the house.

What kind of measures for privacy can be implemented for this? Technically or regulation wise.

Technical defenses are either cat & mouse CSI electronic warfare or shielding the walls+floor+roof+windows of some rooms (e.g. research labs in business, industrial systems, WFH offices, bedrooms) with materials like aluminum radiant barrier, RF window film or expensive drywall (e.g. QuietRock) designed for RF shielding of SCIFs.

Another defense, impractical for most people, is for their house/office to be physically protected by a tall fence that is far enough away from the building to exceed radio range, along with sensors at the fence to detect someone attempting to broadcast into the property. This could be combined with shielding to reduce the necessary fence-building gap.

Regulatory responses: some countries could restrict this technology to high-frequency 60Ghz mmWave which doesn't easily pass through walls. That would at least reduce the social issue of X-ray vision (via 2.4Ghz WiFi) through the exterior walls of existing homes and businesses.

One of the 802.11bf papers proposed an opt-out mechanism where human biometrics could be registered into a giant database and you could ask WiFi devices to unsee some humans. Good luck with that.

Another regulatory response could be to delay approval of Wi-Fi 7 and shipment of Wi-Fi Sensing devices until the WiFi industry pays to upgrade all existing houses with RF shielding, i.e. never. Maybe it would be sufficient to wait until the homes of celebrities and politicians were RF shielded? Let's not forget IP-sensitive and financial business offices with people typing on keyboards. And using combination locks. And...

I wonder how much shielding is actually needed. 2.4 GHz = 12.5 cm wave. A conductive grid with approximately 6cm (or 2") step should prevent the waves from getting inside. Not a very expensive thing to add even to drywall panels. Can also be relatively easily added into fabrics, to make RF-reflective curtains.

Some active device equivalent to a mouse jiggler, retransmitting the signal and shifting the phase just enough to create the illusion of constant movement.

Regulation wise we can hope the EU forces us to click through accept popups whenever we walk into a room.

Absolutely incredible, the applications of machine learning never cease to amaze me.

Will be an absolute boon for VR.

Interesting. Full Body Tracking is one of the few places I can see this getting real end user traction considering how hard it is to do now but a lot of work goes into the pose estimation side and will need to be integrated to the AP. A Modified Microsoft Kinect or Intel Realsense built into their own SoC then it's APIs out to the VR Headset. And at that point it's not just an Access Point anymore.

>Will be an absolute boon for VR.

Ehhh... The latency would need to get lower than camera based systems but it might be useful to some degree.

It doesn't work well if the layout of wifi transceivers it was trained on changes

Interesting. Could be valuable for fall detection without requiring a smart watch.

Why does this sound like exposition from a dystopian Neal Asher trilogy?

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