Securing Time-Synchronization Protocols in Sensor Networks: Attack Detection and Self-Healing

There have been many time synchronization protocols proposed for sensor networks. However, the security problems related to time synchronization have not been fully solved yet. If malicious entities manipulate time synchronization, failures of many functionalities in the sensor networks would occur. In this paper, we identify various attacks against time synchronization and then develop a detection and self-healing scheme to defeat those attacks. The proposed scheme has three phases: (1) abnormality detection performed by individual sensors, (2) trust- based malicious node detection performed by the base station, and (3) self-healing through changing the topology of synchronization tree. Simulations are performed to demonstrate the effectiveness of the proposed scheme as well as the implementation overhead.