Secure and Efficient Time Synchronization in Heterogeneous Sensor Networks

Due to the collaborative nature of sensor nodes, time synchronization is critical for many sensor network operations. For sensor networks deployed in hostile environments, security is critical to the success of time synchronization. Over the past few years, a number of secure time-synchronization schemes have been proposed for sensor networks. However, these schemes are designed for homogeneous sensor networks and may incur large communication/computation overhead or may cause accumulated synchronization errors (due to multihop relays of time reference messages). Several works have shown that better performance and security can be achieved in heterogeneous sensor networks (HSNs). In this paper, we present a secure and efficient time synchronization scheme for HSNs by utilizing powerful high-end sensors. We implement the time-synchronization scheme in real sensor nodes, and the experiments show that our scheme achieves higher synchronization accuracy than a popular sensor time-synchronization scheme. The analyses demonstrate that our scheme is resilient to various attacks and significantly reduces communication overhead.