Security is a prime concern in the resource constrained wireless sensor networks. Traditional cryptographic mechanisms cannot be used with these networks due to their limited battery. Clustering is one of the popular methods to improve the energy efficiency of WSN. In this chapter, the authors propose a secure routing protocol for cluster-based wireless sensor networks. A hierarchical topology is formed by the base station, which is also responsible for distributing the cryptographic keys among the nodes. Security analysis of the proposed protocol is done against various security attacks. The efficiency of the proposed protocol is explained through mathematical calculations and simulations. The proposed protocol also performs better than other existing secure protocols for cluster-based WSN regarding battery life and security overhead.
TopLimited and Irreplaceable batteries make energy conservation at sensor nodes as a crucial design issue for WSN. This becomes important as network lifetime mainly depends upon the energy consumption at sensor nodes. Clustering is a technique that can effectively reduce the energy consumption of sensor nodes and has been widely used in WSNs for data gathering and routing. A variety of clustering protocols have been proposed to address the energy efficiency problem in different network scenarios. Clustering protocols must be designed by appropriately selecting cluster heads to achieve load balancing and hence energy efficiency. LEACH (Low Energy Adaptive Clustering Hierarchy) and LEACH-C (Centralized LEACH) protocols (Heinzelmann, Chandraksan, & Balakrishnan, 2000; Heinzelmann, Chandraksan, & Balakrishnan, 2002) are widely known clustering protocols for two-tiered wireless sensor networks which minimize the energy consumption. LEACH-C is a kind of improved LEACH. This research work has expanded on the LEACH-C protocol to improve wireless sensor networks energy efficiency and security.
Although WSN shares lots of similarity with other traditional wireless networks so the basic security requirements like confidentiality, integrity, authentication, and availability (Carman, Krus, & Matt, 2000; Perrig, Stankovic, & Wagner, 2004) are same as of those networks. However, due to the limited resources, it is hard to apply the traditional security measures with WSNs. Various applications like military or healthcare, a WSN carries sensitive information that helps in making critical decisions. In these scenarios, any interruption in the flow of information may even lead to threats for human lives. So they require a high level of security. An increase in the level of security consumes more resources, this may badly affect the lifespan of the network. Hence, WSN requires high security with minimum usage of resources to ensure the secure data transfer.
There are some existing security protocols based on LEACH, such as SLEACH (Perrig et.al., 2001, Ferreira et. al., 2005), GS-LEACH (Banerjee, Jacobson, Lahiri, 2007)., SecLEACH (Oliveira et. al., 2007), LS-LEACH (Alshowkan, Elleithy, & Alhassan, 2013) and SSLEACH (Kumar & Umamakeswari, 2016). Most of these protocols use the symmetric key encryption for security and increase the storage cost as well as the cost of communication. Which in turn decreases the lifespan of the resource constraint WSN. A secure WSN routing based on secure data aggregation technique was also proposed (Rahayu, Lee, & Lee, 2015) but the energy consumption of this protocol is higher than the other existing protocols.