Researchers studied the signals that are constantly transmitted between Wi-Fi devices and routers during normal network operation. Part of this information, known as **beamforming feedback information (BFI)**, is used to optimize wireless connections and, as it turns out, is transmitted without encryption. By analyzing these signals, researchers were able to obtain a kind of **radio image of a person**. Based on the characteristics of the reflection and propagation of radio waves, the system can determine features of the human body and use them for identification, reports the New York Post. The experiment involved **197 people**. The authors of the study reported that the developed system was able to recognize participants with an accuracy close to 100%. Moreover, the person did not need to carry any electronic device. The technology is based on the use of existing infrastructure. Wi-Fi routers are installed in millions of homes, offices, cafes, and other public places. If such systems learn to interact with each other or if the signals they receive are purposefully analyzed, the wireless infrastructure could theoretically turn into a large-scale covert surveillance system. Researchers are particularly concerned about the possibility of identifying a person **without their knowledge and without direct interaction with them**. For example, a person may regularly walk past a cafe with an active Wi-Fi network, and the system could recognize them and subsequently match them with other observations. Professor Thorsten Strufe from the Karlsruhe Institute of Technology notes that the technology has significant potential but also creates serious risks to privacy rights. According to co-author Julian Todd, in the future, every router could become a potential surveillance tool. It is important to note that this is primarily a **scientific demonstration of the technology's capabilities**, not proof that every household Wi-Fi router is currently monitoring people on its own. Practical mass application would require appropriate equipment, software, access to signals, and infrastructure for analysis. The research shows that familiar wireless signals can contain much more information about a person than is commonly believed. Wi-Fi technologies are gradually transforming from a simple means of data transmission into tools capable of analyzing the physical presence of people. That is why scientists urge the development of privacy protection mechanisms in advance and to integrate them into future Wi-Fi standards. Otherwise, the infrastructure created for convenient wireless communication could potentially become another means of covert surveillance of individuals.
