MagFingerprint: A Magnetic Based Device Fingerprinting in Wireless Charging.

Wireless charging is a promising solution for charging battery-driven devices pervasively. However, the wide deployment of wireless charging stations is vulnerable to the device masquerade attack, which causes financial loss when billing or charging system damages like overheating and explosion. Device fingerprinting is a classical technique to thwart the device masquerade attack. But existing works either are vulnerable to forging or require specialized equipment, which is not suitable for wireless charging.In this paper, we design a magnetic based fingerprinting system MagFingerprint, which utilizes the alternating magnetic signals as the fingerprint and is compatible with existing wireless charging systems. MagFingerprint is convenient for the user since it only employs commercial-off-the-shelf (COTS) magnetic sensors and requires no action from users. In particular, for the charging device, based on its intrinsic manufacturing errors, MagFingerprint generates a unique fingerprint according to the distinct magnetic changes during the wireless charging process. It is shown that MagFingerprint can achieve an accuracy of 98.90% on wireless charging exposed coils, while it is also effective on different commercial wireless charging pads of Apple, Huawei, and Xiaomi.