Invisible surveillance in your living room

Wi-Fi is something we take for granted these days, instantly connecting us to the internet where we spend more and more of our time. However, scientists in Germany have discovered a completely new way to use the technology. They have found that standard routers that we all have at home can identify individuals by analyzing the way radio waves bounce off the human body.

This technology works similarly to a camera, creating an image of people present in a certain space. The user does not even need a smartphone or any other device connected to the network. The signal itself, generated by surrounding Wi-Fi networks, is sufficient to detect and identify people. As these invisible signals move through space, they bounce off objects and people. These reflections create distinctive and unique patterns, which are then analyzed by artificial intelligence systems to identify individuals. By combining multiple different signal reflections, researchers can create a unique profile of a person, based solely on how their body interacts with the wireless signals in their surroundings.

The concept is not entirely new, as the ability to detect movement using Wi-Fi radio signals in homes was first reported in 2012. At the time, it was found that small changes in the signal frequency when reflected from moving objects could create direct impressions of what was happening in the space. Now, a full 14 years later, researchers have taken it a step further and demonstrated that the technology can not only detect people, but can also determine their identity with extreme accuracy.

Unlike smart doorbells and security cameras, this type of monitoring is completely invisible. Since wireless signals are present in most homes, offices and public places, such a system could operate without people even being aware of the surveillance. The research team conducted practical tests involving 197 participants. The results were surprising, achieving almost 100 percent accuracy in identifying individuals.

Because the system runs on standard Wi-Fi infrastructure and requires no specialized equipment, the scientists warn that privacy threats in an increasingly connected world could be extremely serious. Understanding this mechanism will help policymakers develop stronger safeguards in the future.