Using more precise sensors, the same MIT
researchers went on to develop systems that
can distinguish between different people
standing behind walls, and remotely
monitor breathing and heart rates with 99
A system called “WiKey” presented at a
conference last year could tell what keys
a user was pressing on a keyboard by
monitoring minute finger movements.
And a group of researchers led by a Berkeley
Ph.D. student presented technology at a 2014
conference that could “hear” what people were
saying by analyzing the distortions and
reflections in wi-fi signals created by their
Ok that's pretty cool. But incredibly concerning.
The actual abstract of that paper mentions much higher figures for individual keys:
WiKey achieves more than 97.5\% detection rate for detecting the keystroke and 96.4% recognition accuracy for classifying single keys. In real-world experiments, WiKey can recognize keystrokes in a continuously typed sentence with an accuracy of 93.5%.
If I am understanding this thing correctly, WTF...they are figuring out keystrokes by looking at the variations on a WiFi signal caused by the movement of human fingers during typing, which change how the signal propagates!?
Note that the computer you are typing on does not even have to be using WiFi. Heck, you would not even need to be using a computer. This should work if you are using an old manual non-electric typewriter.
So people are really good attenuators of the 2.4Ghz signal and mimo routers in particular are pretty good at localizing where attenuation is happening. That combination makes a WiFi base station a good hardware platform for tracking humans.
As soon as my LimeSDR system arrives I'm looking at trying to replicate some of these results.
edit: I just read the MIT paper, and it's using ISAR. My advisor would be ashamed of me for not realizing that... Still, as the number of antennas continue to increase for better directionality, the wifi radar could even become effective on stationary targets. Soon we'll all be dressed like F-35s to hide from our routers.
I'd be happy if I can add a 'human motion / location detector' I've got ideas for a spotlight system that provides light for you when you walk up to a dark porch.
It needs to know what keyboard/layout and also the person.
I'd guess that the position of the keyboard in the room needs to stay constant too.
I remember WiSee (http://wisee.cs.washington.edu/) a while back and ever since then I thought it would make for a fantastic home security system. You plot out your perimeter and when armed it goes off whenever a person crosses the threshold.
With some of the improvements from this system, it could even be possible to have it always armed but excluded certain people from tripping the alarm.
I wish I had the knowledge and experience to implement such a system (radio-wise).
Google for "SDR passive radar" for some really cool projects.
I might not be such a wizard :-( but still I know some things about how some everyday objects such as computers/laptops (hidden features), mobile phones, WiFi etc. can be used for surveillance. Even in a country such as Germany that has seen two surveillance states in the 20th century and is thus a lot more concerned about surveillance than, say, the US (as I observe it) I'm talking about this topic till I am blue in the face.
So in other words: I don't believe you would consider such a person to be overwhelming, but instead you would consider him as flat-out annoying and paranoid.
As in, everywhere you go, you realize how much information a knowledgeable evil actor could extract by simply analyzing what's being irradiated.
I would liken it to having the ability to imagine another color. They probably don't have an exact idea of the information flowing around them, but they know it is there and they have an ability to reason about it better than others. I can't imagine that's something that is easy to simply leave at the office.
Now it's here again, and I'm even more frightened.
Sneakers - in the beginning when they're spying on Dr. Janek, the team can't see the entire password he types, but Whistler hears the missing keystroke.
And related to the original post, The Dark Knight has Batman using sonar from everyone's mobile phones to detect where the Joker's henchmen were and here we are with wifi routers (and potentially other 2.4 GHz devices).
They're all trying to figure out what the password is from the video, and Whistler is paying attention to what they're saying, which is that he has an answering service. And if he has an answering service, then the answering machine on his desk is hiding something in plain sight.
I'll have to re-watch this sometime soon.
[And if anyone reading hasn't watched Sneakers (1992), you _must_.]
I don't believe that the scene you're thinking of happens. Whistler is pretty impressive, but even he can't hear the difference between keystrokes.
The other cool things that Whistler does are figure out where Martin was taken by the sounds that Martin remembers, and figure out what the various rooms in the building are via telescopic microphone ("Emergency exit stairwell." "How can you tell" "I can hear the emergency exit light batteries recharging") :D
I skimmed over the movie late last night and realised I completely misremembered the two scenes mentioned, and exaggerated Whistler's hearing abilities.
Using 2-factor authentication also helps. Even if the bad guys know the code, it's only good for 60ish seconds. This provides a time dependency, similar to your dial idea.
But the problems of both using 2FA and a private key is that they both rely in something that only you have.
If someone figures out how to steal your phone/hard drive, then they also have their way to all your accounts.
This dial tries to get back to the idea of "something that only you know".
Finally, you could also use a private key with a password, and you would even reduce more the attack surface. But again, the dial is a way to make harder to hear your secret when you're entering it in the computer.
Anyway, this dial is a PITA to enter long passwords, which is not good. Long passwords are very important.
Probably a lot more accurate than (ab)using wifi routers for the purpose, but the benefit of WiFi is that other people have already conveniently installed the hardware inside their homes.
Does this mean I need to shred my tinfoil hat and blow it around the room as chaff?
"Something in the way? No problem. A pair of MIT researchers wrote in 2013 that they could use a router to detect the number of humans in a room and identify some basic arm gestures, even through a wall. They could tell how many people were in a room from behind a solid wooden door, a 6-inch hollow wall supported by steel beams, or an 8-inch concrete wall—and detect messages drawn in the air from a distance of five meters (but still in another room) with 100 percent accuracy.
(Using more precise sensors, the same MIT researchers went on to develop systems that can distinguish between different people standing behind walls, and remotely monitor breathing and heart rates with 99 percent accuracy."
Like Bart Simpson said "No one suspects the butterfly." In this case, no one would suspect their router to be watching where they physically are. Imagine a SWAT team being able to detect where people are within a room before they enter the place - all by snooping through a router.
Sitting here at home (in an apartment building), I can currently count 5 Wifi networks to connect to, and only one of them is mine.
WiFi routers just look like passive boxes. Heck, in an unfamiliar house you might have to go on an expedition to even find the thing, and a router shoved behind a cabinet can track you too.
(It may even make it somewhat worse, as the router's transmitter is less likely to idle. Although I'm not sure if it matters.)