Secure multi-hop routing protocols in Wireless Sensor Networks: Requirements, challenges and solutions

Wireless Sensor Networks (WSNs) have been a subject of extensive research and have undergone explosive growth in the last few years. WSNs utilize collaborative measures such as data gathering, aggregation, processing, and management of sensing activities for enhanced performance. In order to communicate with the sink node, node having low power may have to traverse multi-hops. This requires neighbors´ nodes to be used as relays. However, if the relay nodes are compromised or malicious, they may leak confidential information to unauthorized nodes in the WSN. Moreover, in many WSN applications, the deployment of sensor nodes is carried out in an ad-hoc fashion without careful examination. In such networks it is desirable to ensure the source to sink privacy and maximize the lifetime of the network, by finding secure energy-efficient route discovery and forwarding mechanisms. Careful management is also necessary, as processing required for secure routing is distributed over multiple nodes. An important consideration in this regard is energy-aware secure routing, which is significant in ensuring smooth operation of WSNs. As, these networks deal in sensitive data and are vulnerable to attack, it is important to make them secure against various types of threats. However, resource constraints could make the design, deployment and management of large WSNs a challenging proposition. The purpose of this paper is to highlight routing based security threats, provide a detailed assessment of existing solutions and present a Trust-based Energy Efficient Secure Routing Protocol (TEESR). The paper also highlights future research directions in of secure routing in multi-hop WSNs.