| Time synchronization is critical issue to many wireless sensor network applications such that target tracking, TDMA radio scheduling, and secure localization. However, the most of existing time synchronization algorithms in wireless sensor networks did not consider malicious attacks in hostile environments. In this thesis, we propose a Relative Clock Drift Rate Based Secure Time Synchronization (RSTS) schemes to address security problems. RSTS alleviates delay attacks and incorrect time stamp transmissions caused by external or internal malicious attackers. We discuss a simple estimation technique to calculate a relative clock drift rate between sender-receiver clocks, because the estimated relative clock drift rate is important to detect malicious attacks, when we employ a threshold-based algorithm to calculate bounds of acceptable the offset. We show that RSTS incurs minimal computational overhead. Further, it does not consume any extra bandwidth when it is compared to any other sender-receiver synchronization algorithms. |
