Research On The Security In Wireless Sensor Network

Wireless Sensor Network is a kind of new technology which contains many techniques of other fields such as sensor technology, embedded technology, modern network and wireless communication technology and distributed information processing technology. It is such a wireless network that is made up of widespread sensor nodes capable of wireless communication and computer functions in a self-organizing way. As an intelligent system, it could deal with assigned tasks on its own. Besides the function of environment monitor, Wireless Sensor Network is widely used in military, industry, medical career, communication and intelligent household and so on. However, sensor nodes are deficient in safety because of the following elements, such as the terrible environment in which Wireless Sensor Network is installed, strict limitation of sensor nodes'resources, the wide limits, concentrated distribution and the opening of arrangement areas and the shortage of stable fundamental facilities of network. Once the sensor network is attacked or destroyed deliberately, it may lead to disastrous consequences. Therefore, the safety of sensor network and the limitation of electric power become the very aspects that restrict its wide use in military and business.Digital signature technique plays a very important role in assuring the integrity of information, personal identification and undeniable feature. Although we can prevent the intrusion by the means of encryption, authorization and attestation to some extent, we can't eliminate such a risk. Moreover, once network sensor nodes are "caught", the attacker with a rightful identity can attack the whole network as much as possible which could result in disastrous consequences. Here the intrusion detection called the second line of defense can prevent such kinds of attacks efficiently.Therefore, to begin with, the thesis introduces some elementary knowledge about wireless sensor network, including safety aim, safety mechanism, features of network structure, application fields and current developing situation. Then, it refers to the encryption system of wireless sensor network in detail, analyzes and compares the advantages and disadvantages of three typical encryption systems. It studies digital signature algorithm and comes up with the improved N-ECDSA after it which could avoid making twice inverse operations. C programming language is used to achieve the simulation of the signature algorithm. It assures the high efficiency of operations and the safety, and makes the operations simpler and operation steps fewer. It compares the running time of the improved ECDSA and the classic ECDSA through Matlab.The improved ECDSA reduces the energy consumption of sensor nodes and networks and can be used much properly in wireless sensor network. At last, the thesis tells something about the immunity theory, intrusion detection mechanism and Multi-Agent techniques. It is difficult to make traditional intrusion detection techniques---which easily cause the failure of the single point and are unadaptable-work properly for wireless sensor network because of the dynamic state of the latter. In accordance with such a situation, based on the immune theory, a model structure the Multi-Agent intrusion detection system is put forward by combining the operation theory of artificial immune system with Multi-Agent techniques and applying it to the intrusion detection system of wireless sensor system, during which the main functions and the choosing process of antibody of some kinds of Agents are introduced in the model.