“I spy, with my little Wi-Fi” is a cute title of an article that is quite frightening: Using Wi-Fi to track people inside buildings, when you can see nothing from the outside. Part of me is fascinated, partially because my main business is selling high-tech surveillance and security equipment, the other part of me is horrified by the extent to which “Big Brother” is able to watch us.
Like all radio waves, Wi-Fi signals undergo subtle shifts when they encounter objects, including human beings. These shifts can reveal information about shapes and motion, in the same way that bats navigate, and radar works in submarines.
Jiaqi Geng, Dong Huang and Fernando De la Torre, of Carnegie Mellon University in Pittsburgh, wondered if they could use Wi-Fi to identify the behavior of people inside otherwise unobservable rooms. They tried, and they can, which is the scary part.
Potentially, that means you should be able to download an App on your mobile phone, which will allow you to track anyone inside any building, unless that building or room has a Faraday cage build into it – A Faraday cage is an electronic box that doesn’t allow signals in or out. Currently, that technology is used in security situations to block cell phones being used in private meetings as a way of outsiders having illicit access to the meeting. A Faraday bag for your laptop prevents hacking in airports is another use.
The researchers at Carnegie Mellon are not the first to think of doing this, but previous efforts have been restricted to 2D images based on 17 vector points on the human body; head, chest, knees etc. The new research allows the observer to construct a 3D image based on 24 vector points.
I would think it wouldn’t be long before this technology can create a hologram for the illicit observer that might even be able to identify the people inside the room or building: Even more frightening. However, there is comfort in thinking that the counter-technology of Faraday-like defensive systems will also develop alongside the invasive ones: A “cat-and-mouse” game that is common in all surveillance technologies; for example, naval vessels often turn off their radar sets because it reveals as much about the searcher as it does about the searchee.
The new research has also advanced, actually simplified, the equipment necessary for this type of surveillance. The previous 2D technology needed special “souped up” routers, and other specialized equipment. The new design uses easily-available household routers and equipment.
As with most new advances in electronics, there are good potential uses, and bad ones. The good ones for this new technology include monitoring the well-being of elderly people and uses in interactive gaming and exercise monitoring. The bad ones include illicit surveillance and espionage.
Wi-Fi signals have already been used against us. The Wi-Fi signal that is broadcast by your non-key car-key can be picked up outside your house when the key is on your hall table, cloned, and the clone used to steal your car without the thief having to break into it, for example.
The scientists at Carnegie Mellon have not yet revealed who is funding their research, but another of their projects – developing techniques for detecting specific human behaviors in video-surveillance footage – is paid for by IARPA, the research hub of the U.S. Office of the Director of National Intelligence, which oversees America’s spies.
Even though I am in the business myself, I am still occasionally surprised by the extent to which we have no privacy these day. And I know only a small percentage of what is actually out there. The only saving grace is that the vast majority of us are not interesting enough to warranty expensive surveillance equipment being wasted, monitoring our movements.