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  ARM Give a man a fire and he's warm for a day, but set fire to him and he's warm for the rest of his life (Terry Pratchett, Jingo)

Wi-Fi devices set to become object sensors by 2024 under planned 802.11bf standard

(2021/03/31)


In three years or so, the Wi-Fi specification is scheduled to get an upgrade that will turn wireless devices into sensors, capable of gathering data about the people and objects bathed by their signals.

"When 802.11bf will be finalized and introduced as an IEEE standard in September 2024, Wi-Fi will cease to be a communication-only standard and will legitimately become a full-fledged sensing paradigm," explains Francesco Restuccia, assistant professor of electrical and computer engineering at Northeastern University, in [1]a paper summarizing the state of the Wi-Fi Sensing project ( [2]SENS ) currently being developed by the Institute of Electrical and Electronics Engineers (IEEE).

[3]

SENS is envisioned as a way for devices capable of sending and receiving wireless data to use Wi-Fi signal interference differences to measure the range, velocity, direction, motion, presence, and proximity of people and objects.

It may come as no surprise that the security and privacy considerations of Wi-Fi-based sensing have not received much attention.

[4]

As Restuccia warns in his paper, "As yet, research and development efforts have been focused on improving the classification accuracy of the phenomena being monitored, with little regard to S&P [security and privacy] issues. While this could be acceptable from a research perspective, we point out that to allow widespread adoption of 802.11bf, ordinary people need to trust its underlying technologies. Therefore, S&P guarantees must be provided to the end users."

In 21st-century tech dystopia, smart TV watches you, warns Princeton privacy prof [5]READ MORE

Networking researchers have known for years that Wi-Fi signals can be used for gathering data about nearby people and objects. But to date, such efforts, like [6]trying to capture gesture input via Wi-Fi, have been the province of research projects.

Since 2020, however, the IEEE 802.11bf Task Group has been meeting and exchanging notes about how to modify the IEEE 802.11 standards at both the Medium Access Control (MAC) and Physical Layer (PHY) to support Wi-Fi sensing across existing systems, including 802.11ad, 802.11ay, 802.11n, 802.11ac, 802.11ax and 802.11be.

Restuccia argues the IEEE's standardization effort, in conjunction with the many SENS systems that are apparently being developed, "will create the 'perfect storm' for the introduction into the market of groundbreaking applications that we cannot even imagine today."

We can, however, imagine some of the potential harms.

"Indeed, it has been shown that SENS-based classifiers can infer privacy-critical information such as keyboard typing, gesture recognition and activity tracking," Restuccia explains. "Given the broadcast nature of the wireless channel, a malicious eavesdropper could easily 'listen' to CSI [Channel State Information] reports and track the user’s activity without authorization."

And worse still, he argues, such tracking can be done surreptitiously because Wi-Fi signals can penetrate walls, don't require light, and don't offer any visible indicator of their presence.

Restuccia suggests there needs to be a way to opt-out of SENS-based surveillance; a more privacy-friendly stance would be to opt-in, but there's not much precedent for seeking permission in the technology industry.

There's still much work to be done to resolve interference issues, some of which may arise as a result of having to share the spectrum with other wireless technologies, and to figure out the optimal tradeoff in terms of allocating spectrum to SENS versus having SENS piggyback on existing data packets.

[7]

With any luck, the security and privacy risks will get additional attention too. ®

Get our [8]Tech Resources



[1] https://arxiv.org/abs/2103.14918

[2] https://beyondstandards.ieee.org/ieee-802-11bf-aims-to-enable-a-new-application-of-wlan-technology-wlan-sensing/

[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/networks&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YGRIQKOo1YVGDRU5ChhYLgAAAFE&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0

[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/networks&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33YGRIQKOo1YVGDRU5ChhYLgAAAFE&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0

[5] https://www.theregister.com/2019/10/01/your_smart_tv_is_watching_you_says_princeton_privacy_prof/

[6] https://www.theregister.com/2016/09/28/text_input_from_thin_air_boffins_give_wifi_the_finger_with_ai/

[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/networks&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44YGRIQKOo1YVGDRU5ChhYLgAAAFE&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[8] https://whitepapers.theregister.com/

Chris G

This sounds like something that may well be abused from the first moment abuse is possible, by all the usual data slurpers, Google, Facebook, governments et al.

One thing that could help against commercial abuse is if we all had ownership of our data as a constitutional right, so that each time an entity wishes to use it they must gain your express permission to do so.

Stalker's dream

Christoph

As I understand this story, it implies that a stalker who can somehow get access to a victim's Wi-Fi will be able to prove to their victim that they know exactly what they are doing all the time. It's an obvious extension of things they already do such as planting tracking devices on cars. Many victims will be completely non-technical and have no idea how this is happening.

I don't give a shit what fancy applications can be enabled by this tech - if it enables this it is completely unacceptable.

Not that this will stop it of course - the police forces will insist on being able to do the same thing.

Re: Stalker's dream

Gotno iShit Wantno iShit

It's like so many other technologies, keep it in the home and it could be tremendously useful, e.g. automatic light control without needing dedicated sensors in every room.

As soon as you introduce cloud - FO, FRO then when you finished that FRO some more.

Re: Stalker's dream

Ordinary Donkey

You won't be able to keep it in the home. There are more than twice as many identifiable wifi networks in my home office than there are apartments in the building.

Re: Stalker's dream

AMBxx

Already easier ways to do this. York City Council are very pleased that their free WiFi network allows them to track everyone using the MAC address of their phones. They talk about it all being cuddly and anonymous but if you start from the same place each day, it's not exactly anonymous.

Needless to say, they claim the benefits such as tracking traffic.

I'm sure they're not the only council using such technology.

I now turn off WiFi when I'm out and about.

Re: Stalker's dream

H in The Hague

"... it implies that a stalker who can somehow get access to a victim's Wi-Fi will be able to prove to their victim that they know exactly what they are doing all the time."

Possibly worse than that. If the wall between you and the neighbours is thinish your Wi-Fi system might be able to sense movement in their house. Esp. if you tinker with your system to boost its output.

osakajin

Tin foil hats? Pfft. My Faraday cage suit idea looks set to make me a fortune.

Scott Broukell

@osakajin - But this tech will be in use during the rest of thee week as well, it's not just restricted to Faradays!

Chris Miller

You're a day early with this April Fool.

Anonymous Coward

Seems to be a large well organised jape then, https://www.ieee802.org/11/Reports/tgbf_update.htm

JohnMurray

The movement it will detect last thing at night, is my hand moving to the "off" switch.

anonymous boring coward

It's not April 1st until tomorrow!

I suppose this was inevitable

Neil Barnes

given that people will stick microphones around the house... but what possible reason is there for this technology?

It's a communications protocol, not a motion detector. If you want one of those I'm pretty sure there are other more mature technologies.

Re: I suppose this was inevitable

find users who cut cat tail

The reason is always the same: You would install those more mature technologies intentionally and persumably have some control over their use. Whereas with this you will have little choice as WiFi is ubiquitous.

thosrtanner

I think 'bf' as part of the standard name is remarkably apt really. And sadly, the IEEE website has plenty of information about this idea

what could possibly ever go wrong

Anonymous Coward

Pulse-Doppler radar is, where the frequency dictated the resolution is, not really possible in a shared RF space.

2.4GHz has a wavelength of ~ 124mm

5GHz has a wavelength of ~60mm

60 GHz has a wavelength of ~ 5mm

So I'm guessing that 802.11bf would be a Monostatic radar in which the TX bandwidth is the critical factor:

2.4GHz typically has a bandwidth 20MHz, 40MHz or 80MHz which would correspond to ~15m, 7.5m or 4 meters

5GHz has a channel bandwidth 20MHz, 40MHz, 80MHz or 160 MHz which would correspond to ~15m, 7.5m, 4m or 2 meters

60 GHz has a channel bandwidth 2.16 GHz which would correspond to ~140 mm

And the reason I say Monostatic radar, is that most of the heavy duty math used in demodulation could then be used almost for free with ranging.

Time to go off an start reading some documents on 802.11bf, now that I've made my guess on how it probably works.

Re: what could possibly ever go wrong

Mast1

Look at previous methods of imaging with WiFi, eg this from 2013 :

http://people.csail.mit.edu/fadel/papers/wivi-paper.pdf

And that was using 2.4 GHz.

BTW Why use of public Wi-Fi when mobile small-quantity data contracts are pretty cheap nowadays and the downside of MitM is all too apparent ? Just asking.

Re: what could possibly ever go wrong

Bartholomew

Looks like it is a form of Continuous-wave radar and technically would not be a Monostatic (transmitter and receiver at the same place), It would be closer to a Bistatic radar. But since the transmitters and receivers could both be moving in real time would you then call it a pulsed Bidynamic radar!

It is amazing that the initial building blocks required for WiFi Sensing have been in the standard since 1999 when 802.11a was first released.

From a technical level it is really cool that you can have a mobile radar system map out remote environments, but from an Orwellian perspective it is freakout city.

"way to opt-out of SENS-based surveillance"

alain williams

That should be the default. It should be opt-in.

Question: how do you go about getting the agreement of everyone within range ?

Also: how much more of a drain on the battery will this be ?

Re: "way to opt-out of SENS-based surveillance"

Anonymous Coward

> Also: how much more of a drain on the battery will this be ?

Since most of the heavy math is being used for demodulation anyhow, almost negligible.

Doctor Syntax

"preferably before launch"

Why break the habits of a life time?

Security and privacy still left to fix (if ever)

Mike 137

Convergence is always going to be a problem. It enables cross-contamination, reduces resilience and increases complexity, which in turn reduces security by creating a larger target for attack. Nevertheless it's obviously "the way forward" so it'll go ahead until we have a wonky real world equivalent of the Start Trek tricorder (that could detect and report on anything in the universe and also be re-wired in the field to act as a weapon). Unfortunately life is not quite as portrayed in Star Trek.

The police

Bartholomew

https://www.youtube.com/watch?v=_wsMEj2ZfW8

You got to love the lyrics.

The progress of technology.

muddysteve

your scientists were so preoccupied with whether or not they could that they didn't stop to think if they should.

Dr Ian Malcolm - Jurassic Park 1993

Were they afraid that "e" being the most widely used letter in
the English language was going to war out thir xpnsiv kyboards if
thy usd it all th tim?

- Mike A. Harris on linux-kernel