Privacy at risk: Systems that use Wi-Fi to see through walls are on the way

Use the WiFi signals to see where people are and what they are doing or where technological devices are located, even if it looks like something out of a sci-fi movie, it is already a reality. The level of detail and simplification of systems, recently opened to new privacy issues.

Researchers at Carnegie Mellon University in Pittsburgh (USA) have developed a method that allows this detect three-dimensional shapes and movements of human bodies in a room using only wifi routers.

To do this, they use a system called DensePose (developed by Facebook AI experts among others) that maps all pixels on the surface of the human body and a deep neural network (an artificial intelligence) that maps the amplitude and phase of sent and received Wi-Fi signals to those coordinates on human bodies.

“The results reveal that our model can estimate the location of multiple subjects with a visual performance comparable to that of image-based approaches using Wi-Fi signals as the only input,” says Jiaqi Geng, a technician at the Institute of Robotics of the aforementioned university, in the article in which he summarizes his work.

Also, according to Geng, its system for detecting people using Wi-Fi signals has the advantage that they are not affected by bad lighting or obstacles, which prevent obtaining accurate images with a camera.

Furthermore, says the researcher, offers advantages in terms of costs and energy consumption regarding equipment based on radar technology or laser remote sensing, among other things because most homes in developed countries already have Wi-Fi installed at home.

“This paves the way for low-cost, widely accessible, and privacy-preserving algorithms for human detection,” Geng says.

Because, instead of seeing his device as a threat to people’s intimacy and privacy, this scientist believes it her system protects her because it allows you to monitor the behavior of elderly or dependent people, for example, in a non-invasive way.

The new Wi-Fi technology that detects movements

But Geng’s isn’t the only system using Wi-Fi to see through walls. A team of researchers from the University of Waterloo (Canada) recently presented a device weighing just 10 grams, which can be used by drones or carried in your pocket, and which pinpoint the location of any device Wi-Fi enabled inside a building.

Its developers say the device, called Wipeepexploits a Wi-Fi security loophole which means that, even if the network is password protected, cell phones or other smart devices automatically respond to contact attempts from any other device within its range.

“Wi-Peep sends multiple messages to a device during flight and then measures the response time in each case, allowing it to pinpoint its location to within one metre,” University of Waterloo sources explain.

“Wi-Peep devices are like lights in the visible spectrum, and walls are like glass,” explained Ali Abedi, a professor of computer science at this institution.

Furthermore, the professor said that using a similar technology “someone could track the movements of security guards inside a bank by following the location of their smartphones or watches; or a thief could identify the location and type of smart devices present “. in a home, including security cameras, laptops and smart TVs.

The fact that the device can be operated by a drone means it can also be used remotely, quickly and remotely to make it difficult for the user to be tracked, acknowledges Professor Abedi.

Therefore, researchers from the University of Waterloo are urging specialists to fix this security flaw in Wi-Fi technology (called Polite Wi-Fi) and, meanwhile, are calling on Wi-Fi chip makers to introduce a artificial random variation in the response time of smart devices making it difficult for tools like Wi-Peep to inaccurately calculate their location results.