An Energy-Optimized Secure Routing Protocol For Wireless Sensor Networks

Wireless sensor network is composed of a large number of low-cost micro-sensor nodes which are deployed in the region to be monitored, these sensor nodes form a multi-hop's self-organizing network that can collaborate in real-time detection, sensing and collecting information of a variety of environments or monitored objects, and then transmit informations to distant observers through wireless communication.With years of development, wireless sensor network has gradually become a hot-spot in industry and academic, and has very broad application prospects in scientific research, civil and military fields. As the wireless sensor network's own special characteristics, such as the extreme limited node energy, computing power and communication bandwidth, and flexible network topology, a large number of traditional routing protocols can not be applied to wireless sensor networks, moreover, the routing algorithms that have been proposed in WSN are generally lack of considerations on safety, therefore, how to save and balance the node energy consumption effectively in the premise of certain security is an important research direction.In this thesis, we briefly introduce the architecture, characteristics and research status of wireless sensor networks, analyze the typical flat routing protocols and clustering routing protocols in WSN, and elaborate LEACH in detail. Then, we analyze the advantages and disadvantages of LEACH to propose the improvements. On the one hand, considering that LEACH does not take into account the balanced inter-cluster energy consumption, a protocol based on non-uniform distribution of double cluster heads(NUDC) is proposed, the core idea is based on LEACH's stochastic cluster head election algorithm to elect the main cluster-heads, then according to the threshold to generate the vice cluster head in the clusters which are closer to the base station to share the load of the main cluster head, meanwhile, it transmits data to the base station through the vice cluster heads and intermediate nodes, thus reducing the energy consumption of cluster heads which are far away from the base station and extending the life cycle of the network. On the other hand, we analyze the common attacking types of routing protocols in wireless sensor networks and propose a security solution of NUDC protocol(NUDC-S), it uses the key pre-distribution scheme to generate keys in cluster communication and inter-cluster communication to encrypt data transmission process, thereby enhancing network's security.We simulate NUDC and NUDC-S in the NS2 simulation platform, the results show that, NUDC balances the energy consumption and extends the life cycle of the network. Although the energy consumption of NUDC-S is slightly increased, it improves the network's security to a certain extent.This thesis is supported by National Natural Science Foundation of China (No: 60773211,60672137,60970064),Open Fund of the State Key Laboratory of Software Development Environment (No:SKLSDE-2009KF-2-02),New Century Excellent Talents in university (No:NCET-08-0806),Fok Ying-Tong Education Foundation for Young Teachers in Higher Education Institutions of China (No:121067),NSF of Wuhan Municipality (No:201010621207),Specialized Research Fund for the Doctoral Program of Higher Education of China (No:20060497105) and the National Science Foundation of HuBei Province (No:2008CDB335).