Researchers Use Ordinary WiFi Connections to Create Images of Nearby People and Their Surroundings (sciencedaily.com) 27
Science Daily reports:
Researchers showed that unencrypted signals routinely exchanged between WiFi devices and routers can be used to create radio-based images of people and recognize them within seconds. In tests involving 197 participants, the system identified individuals with nearly 100% accuracy, even from different angles and regardless of how they walked. "By observing the propagation of radio waves, we can create an image of the surroundings and of persons who are present," says Professor Thorsten Strufe from KASTEL, KIT's Institute of Information Security and Dependability. "This works similar to a normal camera, the difference being that in our case, radio waves instead of light waves are used for the recognition," explains the cybersecurity expert.
Because the technique analyzes radio waves moving through a space, a person does not need to have a phone, smartwatch, or other WiFi enabled device with them. "Thus, it does not matter whether you carry a WiFi device on you or not." Even turning off your own device would not necessarily prevent the system from working. "It's sufficient that other WiFi devices in your surroundings are active...."
Connected devices routinely send information back to the router to help optimize wireless communication. These signals, known as beamforming feedback information (BFI), are transmitted without encryption, meaning that anyone within range can potentially read them. By analyzing that information, the system can generate images of people from multiple viewpoints. Those images can then be used to determine a person's identity. Once the machine learning model has already been trained to recognize individuals, the identification process takes only a few seconds.
Because the technique analyzes radio waves moving through a space, a person does not need to have a phone, smartwatch, or other WiFi enabled device with them. "Thus, it does not matter whether you carry a WiFi device on you or not." Even turning off your own device would not necessarily prevent the system from working. "It's sufficient that other WiFi devices in your surroundings are active...."
Connected devices routinely send information back to the router to help optimize wireless communication. These signals, known as beamforming feedback information (BFI), are transmitted without encryption, meaning that anyone within range can potentially read them. By analyzing that information, the system can generate images of people from multiple viewpoints. Those images can then be used to determine a person's identity. Once the machine learning model has already been trained to recognize individuals, the identification process takes only a few seconds.
Wired-Only Wireless. Version 6. (Score:2)
If u get a device with WiFi the first thing u should is disconnect the antenna.
Well, yeah.
I mean, who is the insane person buying a wireless device for the wireless capability?
Clearly this is a use-case/sales pitch for Wired-Only Wireless, a necessity for the modern NutterNet. Have a need to network more than a toilet-flush away from the router? Best get your crimpin' hand ready for those late-night LAN wiring sessions if you wanna sesh with the rest of the social mediaites.
Wired-Only Wireless. Brought to you by RoncAcme Industries.
Re: (Score:2)
For example, you can get digital picture frames around your house. Change the picture contents depending on who is closest. Change the lighting in the room automatically based on who is in there.
Re: Disconnect the antenna (Score:2)
You should add more antennas and pump our some disruptive signals to blind this tech
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Where are all the creepy jokes? (Score:2)
'Nuff said?
I told you (Score:5, Funny)
People thought that I was crazy for wearing this sharply angled black stealth suit.
Who's laughing now?
Re: (Score:3)
You're this guy [xkcd.com].
Show me an example (Score:2)
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There are no images at all in the original paper. Haven't read it yet.
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seems everywhere is becoming a surveillance state and gov't and big tech won't give up even if they lose some battles with rich assholes like Larry Ellison saying "citizens will be on their best behavior because we're constantly recording & reporting everything"
Dupe? (Score:1)
Could have sworn I've seen a Slashdot story on this a few months ago.
Re: (Score:2)
The same site ran the identical story in May of 2026. It's even linked at the bottom of TFA. Can't blame Slashdot for duping a dupe.
Baby steps (Score:5, Informative)
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Is using BFI novel? I hadn't seen that before personally.
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- sorry, I'll see myself out.
Finally (Score:1)
Frankly (Score:2)
A far more newsworthy and interesting story was how they hack into pcs using the speaker
Tinfoil (Score:3)
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Is This Not RADAR? (Score:2)
What is the difference between this and RADAR?
The pitch seems to be that a WiFi device could do presence detection and some how use that against you. How they could use that against me has me scratching my head. But, I do feel like I should be scared. So, they've got that going for them.
Re: (Score:2)
The only difference is the frequencies used and the off-the-shelf nature of the devices.
I think this is great. Now everyone can own a TSA grade body scanner, but one with no government oversight. After all, how is a person going to know if they've been wifi body scanned, or just close enough to use the wifi?
hats (Score:2)
I see a new market for tinfoil hats. Or maybe tinfoil suits.
JHFC ACM (Score:2)
This is likely the proceedings with the paper:
https://dlnext.acm.org/doi/epd... [acm.org]
It appears the ACM PDF reader loaded an 850MB PDF into my phone's browser and has been stuck doing a search on "beam steering" for ten minutes.
No joke, I read ACM papers on information retrieval and human computer action three decades ago and this is just hostile design.
I'll try again on my desktop at home tomorrow but maybe somebody can extract the paper before then.
And, yeah, as others have said this is old (November 2025) but