Secure Network-Wide Clock Synchronization in Wireless Sensor Networks

Clock synchronization is of critical importance for several applications in wireless and mobile sensor networks; for example to determine the order and time of events. Although several protocols to achieve clock synchronization have been developed, they may not be secure. For instance, a link controlled by an attacker could delay packets it forwards in ways which would cause the nodes sharing that link to obtain faulty time estimates. In this paper, we propose a secure network-wide clock synchronization protocol. It also allows nodes to securely discover the network topology by detecting and isolating links that behave inconsistently. This network-wide clock synchronization protocol is built on ideas in [1] where inconsistent attacks are detected using timing information alone under certain conditions. The proposed protocol has been implemented and the results of experimentation on a twenty-five node network are presented.