Side-Channel Based Device Authentication in Wireless Charging: An Experimental Study

As wireless technologies increasingly occupy the digital landscape, wireless charging services for smartphones and related accessories have taken a leap forward. In this context, the ability to authenticate and distinguish devices has become a paramount necessity for maintaining consistent service quality and user satisfaction. In this study, we implement an efficient and cost-effective side-channel based device authentication system. Our approach primarily focused on harvesting side-channel data from Qi wireless charger voltage measurements, thus developing a procedure that is not confined to a specific protocol. To implement this authentication framework, we developed a model that classifies devices by continuously monitoring voltage fluctuations in a wireless charging environment, and learns from these observations. We conducted validation experiments using four products from two different smartphone manufacturers. Our results show that the manufacturer of a mobile device can be identified with an exceptional 100% accuracy by relying solely on the voltage readings obtained from the Qi wireless charger. Moreover, our method can distinguish among four devices with different models with an accuracy of 92%. By adopting such a side-channel based device authentication system, service providers can mitigate the risks associated with unauthorized access by unauthenticated users. Our groundbreaking findings may also contribute to the development of a robust and scalable architecture for device classification and authentication in wireless charging environments.