Researchers from the Karlsruhe Institute of Technology have developed a method that allows people to be identified and their movements tracked using only Wi-Fi signals, even if they have no smartphones or other connected devices.
Researchers from the Karlsruhe Institute of Technology (KIT) have demonstrated a method for identifying and visualizing the presence of people using only the Wi-Fi signals in their environment. The approach does not require the person to carry a smartphone or other connected device; it only requires that standard routers and client devices be active in the space, as reported by Interestingengineering.com.
The team showed that analyzing the subtle interactions of radio signals and backscatter information (Beamforming Information, or BFI) allows for the reconstruction of detailed “radio images” of people’s posture and movements, comparable in information content to a camera’s video frames, but constructed entirely from radio waves. In an experiment with 197 participants, researchers trained a machine learning model and achieved nearly 100% accuracy in recognizing individuals regardless of the viewing angle or walking style.
The key danger of the method is its universality: it does not require specialized equipment or network hacking to work, only the observation of interactions between standard Wi-Fi devices. As the authors note, even if people’s devices are turned off, the system extracts information from other active access points and clients. This turns ubiquitous Wi-Fi networks into a potential “surveillance infrastructure” accessible to government services or malicious actors.
The scientists warn of serious privacy implications and call for a discussion of regulatory measures and technical countermeasures (such as improved protocol protection, BFI encryption, or the development of signal “noise” masking methods). The developers emphasize that the technology opens up new research opportunities for analyzing movement and behavior indoors but requires strict rules of application to avoid violating human rights.
