Privacy-Preserving Large-Scale Location Monitoring Using Bluetooth Low Energy

Wearable devices such as smart watch and bracelets continually broadcast Bluetooth Low Energy (BLE) signals, which can be easily captured by monitoring devices such as WiFi routers and Bluetooth scanners. As more and more wearable devices emerge, unauthorized monitoring and tracking by adversary becomes great privacy threats not only in the cyberworld, but also in the physical world. To protect location privacy, this paper presents a real-life location monitoring system that is based on BLE privacy feature that changes the device physical address periodically. To enable users to better control their privacy level while still providing monitoring and tracking service to authorized parties (e.g., for child and elderly care), we extend BLE privacy by enriching its privacy semantics with a comprehensive set of metrics, such as simple opt-in/out, k-anonymity, and granularity-based anonymity. The system has been implemented and evaluated in terms of accuracy and user study.