Imagine that every time you move around your house, the WiFi router not only gives us internet, but it is also drawing a precise map of our body, identifying whether we are cooking, writing on the computer or playing in front of the TV. This, which sounds like science fiction, is the alarming conclusion of a recent study by the Karlsruhe Institute of Technology (KIT) in Germany.
The authors, led by Julian Todt, point out that The latest generation of WiFi, operating in the 6 GHz band, has an unprecedented capacity for recognizing human activities.
Todt’s team will present the results at the ACM Conference on Computer and Communications Security (CCS) in Taipei, and the study will be available starting October 13. The reality is that it is not just any WiFi signal. The study focuses on the WiFi 6E and WiFi 7 standards, which use the 6 GHz spectrum. The critical advantage of this band is its shorter wavelength.
“A shorter wavelength translates into a much finer spatial resolution,” explains Friedemann Dressler, co-author of the study, in a statement. the difference between trying to paint the details of a face with a thick brush or with a single bristle brush. 6GHz WiFi is our single bristle brush. “It can discern with incredible precision the small movements of the fingers, the head or the torso.”
It is logical that we compare this with radar technology. While traditional radar systems for human monitoring use longer wavelengths (and therefore have lower resolution for fine details), 6 GHz WiFi signal can “illuminate” the contours and movements of the body with a detail that was previously believed to be impossible outside of specialized laboratories.
The interesting thing is that the technology does not require cameras or microphones. It works by analyzing the disturbances in the WiFi signal caused by our bodies when moving. When a person moves in the coverage area, their body reflects, diffracts and attenuates the signal. Then a receiver (which could be the same router or another device) captures these alterations in the signal.
Using artificial intelligence and machine learning algorithms, the system is able to interpret these disturbance patterns. Not only does it detect that there is something moving, but it can infer that it is a person, identify what specific activity they are doing (typing, walking, lying down) and even distinguish between different individuals based on their silhouette and way of moving.
The implications of this technology are enormous and, simplistically, you could divide them between legitimate and illegitimate. Among the first we have telecare for older people (allows falls to be detected in real time without the need for wearables or invasive cameras). It would also facilitate the development of context-sensitive home automation, for example, having lights and temperatures automatically adjust based on what the user is doing.
Obviously, we have the security section, such as detecting intrusions with a precision that infrared motion sensors cannot achieve. However, the warning from Todt’s team is clear: The same technology that enables these wonders opens the door to a new level of covert surveillance.
“The danger is the normalization of surveillance – the statement concludes -. Any modern router has the necessary hardware. It only takes one malicious software update to turn an innocuous home device into a spy. “A malicious hacker, or even an advertising company, could collect intimate behavioral data without the slightest knowledge or consent of the user.”
For this reason, Todt’s team has not only launched an alert, but is also working on countermeasures. They suggest that The solution must come through proactive regulation and the development of technical countermeasures.
The line between a smart home and a monitored home has become as thin as the wavelength of a 6 GHz signal. The debate about privacy in the digital age has just entered a new and critical dimension.