Thread by @WriteArthur

Ok so it turns out that your WiFi router might soon be able to spy on you 🧵

In a story for @TheEconomist, I wrote about recent experiments by a team at Carnegie Mellon that demonstrated how to turn the WiFi signals in your home into a detailed 3D digital portrait of your movements.
economist.com/science-and-te…

The science here is pretty fascinating...

Basically, WiFi signals undergo subtle shifts upon encountering objects—including human bodies. When the signals are picked up again and deciphered with an algorithm, these perturbations can reveal information about the shape and motion of those bodies.

It's a phenomenon *very vaguely* akin to the way a bat’s chirps reveal the presence of obstacles or prey in their path.

While all this has long been known to science, this new study claims to have achieved WiFi-based body tracking capabilities equivalent to video-based systems. That's a big leap. Here's the full paper:
arxiv.org/pdf/2301.00250

All the more notable is that the team says it achieved this using regular, off-the-shelf WiFi routers. Previous studies used more powerful versions of WiFi that aren't available for domestic use.

This is, to put it mildly, rather significant.

Unlike cameras, WiFi can track you in the dark. It's way cheaper than equivalent wireless tracking sensors like LiDAR. Plus it can—deep breath—see through walls.

The surveillance applications here are obvious. Anywhere there's WiFi, you could be watched. Though it doesn't work outdoors (for now, at least).

One of the more harrowing possibilities I came across in my reporting was that hackers could potentially tap into your WiFi signals and use them to "watch" you inside your own home.
news.uchicago.edu/story/how-hack…

The Carnegie Mellon team declined to say who was funding this research. Though one of their other projects is paid for by IARPA—the US intelligence community's version of DARPA.

But don't go wrapping up your router in tinfoil just yet. At the moment, commercial WiFi routers don't have built-in tracking capabilities. However, they will soon...

As you read this, IEEE is developing new standards for manufacturers to build tracking capabilities directly into commercial routers. The standards could be ready as soon as next year. standards.ieee.org/beyond-standar…

I know IEEE standards-setting sounds pretty dull. But the manner in which the new standards address these newly demonstrated capabilities could have tremendous implications for your privacy.

In short, keep an eye on all this, lest your WiFi start keeping an eye on you.

NB it turns out some of this stuff *could* actually work outdoors...

https://twitter.com/mattbeane/status/1618643453101101056