  With the increasing popularity of the Internet of Things(IoT) devices, the
demand for fast and convenient battery charging services grows rapidly.
Wireless charging is a promising technology for such a purpose and its usage
has become ubiquitous. However, the close distance between the charger and the
device being charged not only makes proximity-based and near field
communication attacks possible, but also introduces a new type of
vulnerabilities. In this paper, we propose to create fingerprints for wireless
chargers based on the intrinsic non-linear distortion effects of the underlying
charging circuit. Using such fingerprints, we design the WirelessID system to
detect potential short-range malicious wireless charging attacks. WirelessID
collects signals in the standby state of the charging process and sends them to
a trusted server, which can extract the fingerprint and then identify the
charger.
