Passive Wi-Fi: Bringing Low Power to Wi-Fi Transmissions
usenix.org
usenix.org
Connecting RF-Powered Devices to the Internet : http://iotwifi.cs.washington.edu/
3-D printed objects connect to WiFi without electronics : http://www.washington.edu/news/2017/12/05/in-first-3-d-print...
Also there was https://github.com/seemoo-lab/mobisys2018_nexmon_software_de....
If you think about it, there are a lot more things that can be done with wifi if you can arbitrarily TX/RX signals. In fact I'm getting a bit scared now.
The closest thing I can see them mention in that paper is their adoption of the "zig-zag scanning" rather than raster scanning. But how many pixels that skips over is very variable dependent on the input image.
There's also the "super-pixels" thing, but that's pretty standard for video compression right? Macro-blocks and B/P-frames, corrected with occasional full-resolution I-frames...
They also note the effect of distance, both in the abstract and in the results.. 720@60 at 10 feet, but only 480@10 at 16 feet. Not remarkable results, but they're not lying in their abstract...
Lets try 720@10fps. Budget is 3MB per 8 seconds. 64x36@10 L frames = 184KB, 921KB I frame, leaves us with 236KB/s, enough BW to transfer at max only ~20% of changed super-pixels per second. Even their simulated demo video doesnt appear to be real.
Things just dont add up.
...Yes? Gateways (routers) are there anyways.
>For large deployments, that would require many powered units.
As in all deployments?
>In addition to that, there are requirements for multiple MACs, which may also lead to problems with limits in some networks.
Wot? This is a non issue.
>This is all clever, but it doesn't seem practical to me since the passive device depends on a near by powered device to do anything. I have worked on sensor networks with battery powered wifi devices. It's certainly tricky.
Then you don't understand what this is about.
Backscatter is awesome because you literally don't put energy into generating rf yourself.
Can't we have PDF.js decode and render .pptx files? I bet they're no more complex than PDF.
Now, what on earth is a benevolent adversary?
For example in France we had a group of anti-muslim people provide free food to the homeless but the food had specifically pork in it.
Or linked to a recent HN story a vegan terrorist could infect himself with that tick that renders you allergic to meat and then go donate blood for saving children.
If you find yourself a target of one, it means you're most likely evil.
(Also, in less extreme sense, I'd classify hackers as such, i.e. people exploiting systems for fun and learning, without doing any harm to anyone.)
Or anyone who's role it is to test the sturdiness of a system or product etc.
There might be interesting attacks with other high-power antennas in the region creating pockets of destructive interference -- essentially localized denial-of-service type stuff.
The other risk you're taking is something like "the operator of this antenna can induce bit flips and such in your communications," which is true, but they wouldn't know what bits they're meddling with because they have to commit to the inconsistent signal before you use it. But they can already send arbitrary local packets pretending to be you at that granularity. Certainly if we're talking about the signal source managed by the WiFi operator, there is no dispute that this doesn't empower them -- they own the router, where they already have direct control over your internet communication and what they "hear from" and "say to" you.
Compared to the threat of opening your own access points with a suggestive name and just letting people connect to you, which you can also do with this range, being able to meddle with packets in a haphazard way doesn't seem very scary.