Detection and Localization of Hidden Wi-Fi Cameras

The widespread availability of Wi-Fi networks in our workplaces, schools, hotels, and public spaces provides us with access to the Internet from just about anywhere. An increasing range of devices are being developed with Wi-Fi capabilities including devices such as surveillance or "spy" cameras that allow for remote viewing of a live feed. News reports have shown hidden cameras being placed illegally, or without consent, in places including hotel rooms, workplaces, schools, and rental homes. This is a malicious invasion of privacy and has potential to facilitate extortion or blackmail. Current methods of finding hidden cameras typically involve manual surveying of the environment, radio frequency detectors, or the use of some smartphone cameras that cause infrared light to become visible. These methods can be ineffective, unreliable, or incur extra costs for hardware. The addition of Wi-Fi functionality in these maliciously placed devices, while enabling ease of remote viewing and access for the intruder, also creates a means of identifying and localizing them. In this paper, we investigate potential signal metrics to detect and localize hidden Wi-Fi cameras. We use signal metrics such as Received Signal Strength Indicator (RSSI), Channel State Information (CSI) and Power Delay Profile (PDP) to determine the direction of the received Wi-Fi signal as well as estimate the distance to the hidden Wi-Fi camera. Our results show that these signal metrics can be used to detect and localize a hidden Wi-Fi device, with the CSI and PDP signal metrics achieving the best performance in scenarios with line-of-sight and non-line-of-sight to the hidden camera.