A Research On Security Technology Of Wireless Sensor Network

Wireless Sensor Network is (WSN) composed of a great number of sensor nodes by means of wireless communicational technology and self- organization mode. It has a wide applicable prospect in the civilian aspect and the military aspect, but at present, the researches about WSN still have a lot of questions to solve, such as:routing protocol, location technology, network security. The thesis is aimed at the security issue of WSN, mainly conducting a research in the effective detecting mechanism and the method of security location under condition that the WSN is attacked by Sybil. Submit the major research contents and creative results as shown below:Location technology is one of the significant technologies of WSN. WSN technology establishes spatial relationship depending on node's position to report monitored incident. In addition, node's position, which can help routing and other network functions, also an essential basis. However location of network node is easy to be attacked by enemies, because WSN is mainly used under the hostile and unguarded environment. The frangibility depends on the importance of security issue in the process of location.The thesis studies the security location mechanism of sensor network node under the attack of Sybil, and analyzes the safe attacks which are possibly accepted and safe requirement in the location system. Since RSSI possesses the energy transmission function, different transmission energy will cause to produce different RSSI readings. Furthermore, this kind of method can not increase burden on WSN. It conducts an analysis between two receiving nodes, compares RSSI ratios to tickle the problem of time inconsistency of RSSI, and sets a threshold to detect Sybil by the emulation results. Research shows that ratio value of different receiving nodes by using RSSI can resolve time difference because of the RSSI or unreliability which results from asymmetry of transmission ratio. The thesis makes a comparison that the number of receiving nodes has an influence on attack effect. Utilizing the RSSI ration values can exactly detect Sybil attack. Emulation findings demonstrate that the detection method put forward by the thesis owns better security.In the communication network, route algorithm is an essential problem of network layer and its main function is guiding subgroup how to reach exact destination node by sub-network. In the WSN, messages need to get pass many nodes so that they can reach destination. What's more, WSN is characterized by dynamic feature and AD hoc network. Thus, each node is all supposed to have routing function.Because each node is potential routing node, attacked area is larger. First of all, algorithm theory based on the general structure considers credit evaluation of node and influence of Sybil attacking parameter on routing establishment, routing path choice and data transmission. Emulation results state clearly that improved and credible DD algorithm has good security under the attack of Sybil.It becomes extremely difficult to control every detail and every user from the system, partly because of the increase in systematical complex and large number of users, partly because of impact of outside attack. Intrusion Tolerance System is the third generation of network security technology, which studies how to effectively shield or stop damage caused by intrusion when system is suffering the intrusion. The tolerance algorithm of Sybil attack puts forward assumption of deviation by using redundant feature of compared message appears in the system. Utilizing unbiased estimation of variance as the basis of security inspection, the thesis finds out a smallest safe aggregation of comparison at random and uses prediction residuals to diagnose whether the rest of compared data are normal or not one by one in order to improve the ability of system tolerance attack. The experimental results state the algorithm efficiently improves the ability of resisting location attack.