A Secure Time Synchronization Protocol Against Fake Timestamps for Large-Scale Internet of Things

For large-scale Internet of Things (IoT), which located in the hostile environment where exists malicious nodes (MNs), the security of time synchronization is a critical and challenging issue. The malicious sensor nodes could decrease the accuracy of the whole network by broadcasting fake timestamp messages. In this paper, we propose a secure time synchronization model for large-scale IoT. In this model, a node utilizes its father node and grandfather node to detect the MN. By employing the model, a spanning tree topology which synchronizes to the reference nodes can be constructed hop by hop. Then a secure time synchronization protocol is developed to against fake timestamps, which adopts the secure model. We use NS2 as the simulation tool to evaluate our protocol, and compare the impact of fake timestamps in various circumstances with the pervious protocols TPSN and STETS. The experiment results show that our protocol is effective to prevent attacks from MNs.