Abstract

Background: Recent technological advancement in the field of wireless communication, wireless sensor networks have emerged as an effective solution for many applications such as pollution monitoring, military applications, health applications, seismic studies, under water studies, etc. The sensor nodes are deployed in a distributed manner and the clock of these nodes represents different time. Therefore, time synchronization is very important aspect in wireless sensor networks. Time synchronization assures that all the sensor nodes in wireless sensor network have the same clock time. There are various applications where secure time synchronization in wireless sensor networks is required. Secure time synchronization in wireless sensor networks require time message confidentiality, integrity and authentication. Wireless sensor networks suffer from various attacks such as data integrity attack, man-inmiddle, replay attack, etc. Most of the existing time synchronization techniques are not designed with security provisions. This paper proposes security solution for time synchronization in wireless sensor networks with the objective to ensure message integrity and message authentication in an energy efficient manner. Simulation results exhibit that proposed scheme is suitable to ensure security for time synchronization in wireless sensor networks in an energy efficient manner.

Results: The performance of proposed algorithms Secure Time Synchronization (STS) and Clustered Time Synchronization without security (CTS) have been evaluated, and then compared with Timing sync protocols for sensor networks (TPSN) and Two-hop time synchronization (TTS). The performance evaluation includes message complexity and energy consumption.

Conclusion: It is mandatory to identify the security requirements of the applications. There are various applications where energy is mandatory requirement as compared to security. However, there are some applications such as health and military where security is crucial factor as compared to energy consumption. It is very important to consider the capacity of the nodes (processor, memory and energy) while developing the secure time synchronization protocols. In critical applications time synchronization is very important to know the exact time of the event. The proposed Secure Time Synchronization (STS) scheme uses two symmetric keys and hash function to ensure the synchronization of the nodes with security of the message travelling in wireless channel. The objective of STS is to avoid replay attack, integrity attack and man-in-middle attack and ensure synchronization with better precision. Simulation results show that the proposed algorithm save the energy along with security features as compared to other non-secure synchronization protocols. This enhance the network lifetime.

Keywords: Security, time synchronization, WSN, attacks on nodes, processor, sensor nodes.

Graphical Abstract