Research On Security And Optimization For Routing Protocols In Wireless Sensor Networks

Recent advances in wireless communications, embedded computing technologies, computing technology and micro-electro-mechanical systems technology, it is attention-getting for people to research on wireless sensor networks (WSNs), which have enabled the development of relatively inexpensive and low-power-consumption micro sensors with the capability of sensing, computing and communicating.It could be widely used for wireless sensor networks among many areas including military affairs, manufacture control, city management, health and medical care, environmental monitoring, emergency rescue, remote control over dangerous district and other commercial applications. However, in all WSNs, the responsibility of routing protocol which is the most important protocol for communication in WSNs is to deliver data between source and destination nodes. Along with WSNs becoming hot spots in research and industry, the security aspects of routing protocol in WSNs attract attentions of both researchers and engineers. To achieve the communication security in sensor network, key management for wireless networks security plays a fundamental role. However, Due to the intrinsic properties of wireless sensor networks (such as large scale, unknown location, low computing power, the restriction of the storage space and battery power, etc), the traditional security technology based on public key or trusted key distribution centers can not be applied in it. The sensor node has limited resources and communicates in public, so sensor networks also face the other serious security problem. The current routing protocol is vulnerable against attack methods such as wormhole attack and sybil attack. Therefore, the all-important aim is to design a scheme of key distribution and a secure routing protocol for WSNs through integrating the energy efficient into WSNs' security.Multicasting is an important operation used for delivering control message, alarming, multicast information, route discovery, and even direct routing. The different features of wireless sensor networks make the traditional routing algorithms can not be applied efficiently to them. The straight forward solution for broadcasting in wireless sensor networks is flooding (blind flooding), however blind flooding is improper in wireless sensor networks since it consumes too much energy and bandwidth which are deeply constrained in wireless sensor networks, and results in serious redundancy, contention, and collision. The nodes of wireless sensor network have very limited energy in most application environments, and the energy consuming can directly affects the lifetime of wireless sensor network. So it is of great significance for us to research on how to reduce the energy consuming of routing and multicast routing in wireless sensor network, and how to optimize them effectively according to some application effectively.Grasping the two main features including limited resource and widely special application, enclosing the two centers including routing protocol and topology structure, we gradually research on the security and optimization for routing protocol in WSNs. In this paper, to aim at extraordinarily limited energy in WSNs, we particularly research on secure routing protocol, optimization of multi-path routing protocol and multicast routing for WSNs in this dissertation based on routing protocol and scheme of key distribution, and design some related models, and propose some original algorithms to effectively prolong network lifetime, to resist some attacker, and to improve the network performance in WSNs.Firstly, to aim at Architecture of Circle and Wedge Training in WSNs (ACWT), A novel routing technology based on circle and wedge trained (CWR protocol) for wireless sensor networks is proposed, which is consist in the new energy-efficient access point (AP) election algorithm, local position resolution protocol (LPRP) and the network position translation (NPT). Compared to the other routing protocol applied to the architecture of circle and wedge in WSNs, CWR protocol can extend network lifetime and reduce transmission delay.Secondly, To solve the limitation of combination between traditional key management and routing information, we present with improved scheme of polynomial key pre-distribution (PKPIS) based on-demand routing protocol according to the security requirement. PKPIS originally integrate routing information into the scheme of polynomial key pre-distribution, and solve the problem of energy limitation. The scheme makes full use of the topology information of routing and the function of the base station, which gathers the important security information and the computing loads, in order to insure the sensor only to store the polynomial quantum of neighbors. The mechanism not only effectively prevents the key from giving away and improves the network secure performance, but also saves the energy resource.Thirdly, according to severely limited resource presented by WSNs, especially the energy limitation, to provide as much security to the application as possible, we propose an Efficient Routing Protocol Based on Encryption and Authentication for WSNs called BEARP, which solves the difficulty of combination between the routing protocol and the related secure mechanisms. It consists of three phases:neighbor discovery phase, routing discovery phase, and routing maintenance phase. BEARP encrypts all communication packets and authenticates the source node and the BS (Base Station), and it ensures the four security features including routing information confidentiality, authentication, integrity and freshness. Furthermore, we still design Routing Path Selection System, and Intrusion Detection System, and the multiple-threaded process mechanism for BEARP. Thus, all the secure mechanisms are united together to effectively resist some typical attacks including selective forwarding attack, wormhole attacks, sinkhole attacks, and even a node captured. Our BEARP also mitigates the loads of sensor nodes by transferring routing related tasks to base station, which not only maintains network wide energy equivalence and prolongs network lifetime, but also improves the security mechanism performed uniquely by the secure base station.Fourthly, to solve the difficulty of the globally optimization to energy resource, we originally integrate the basic principle of genetic algorithm (GA) into the routing protocol in WSNs, and propose an algorithm called GAMR (Multipath Routing Based on Genetic Algorithm). The presented algorithm adopts variable-length chromosomes to encode the problem, applies selection, crossover and mutation, makes full use of the information and function of the base station, and implements the global optimization for the multi-path routing in WSNs.Lastly, we propose a novel genetic algorithm based on extended sequence and topology encoding (GAEST) for the multicast protocol in two-tiered WSNs. We originally solve the difficulty of the optimization to the multicast protocol with the theory of genetic algorithm. GAEST has a power and energy model to reasonably adjust Euclid distance of cluster head node (CN) according to transmission power calculated by fitness function in GA, and globally optimize the consumption of multicast routing. Moreover, extended sequence and topology encoding, which associates three genetic operation including chromosome selection, chromosome crossover and chromosome mutation, makes best use of some crucial information in a node, and reduces the solution space which gives genetic algorithm the ability of global search to a far away point. Simulation results show that GAEST increases the packet delivery ratio and fitness value in comparison with GAP, and still obtains the optimal convergence speed from different crossover or mutation probabilities, and prolongs the lifetime of multicast service compared with Efficient Multicast Routing Protocol (EMRS) and Directed Diffused protocol (DD).In a word, our achievement of the security and optimization for routing protocol in WSNs is the base of security infrastructure of WSNs. It is really valuable to research on low energy and attack resistant cryptography, secure localization technology, secure data aggregation and optimization in the future.This work is supported by the Ministry of Education Technology Research Key Foundation of China under Grant No.104086.