Privacy And Query Technology Research For Wireless Sensor Network Application

In wireless sensor networks(short for WSN), due to the limited energy of sensor nodes and restricted bandwidth of networks, how to utilize the limited resource to reduce the energy consumption of sensors is becoming one of the recent research hot spots, at the meantime, the problem of network security is highly emphasized, so that privacy protection has been more and more important with the wide application of WSN. Top-k queries, being significant queries in many applications of sensor networks aims to find the top-k network data that users want. This dissertation considers Top-k query with privacy protection and privacy protection query in scenario finding common parking spaces.Based on the research of wireless sensor network, we analyze the query problem and the privacy protection question. Then we propose an exact Top-k query algorithm with privacy protection based on data distribution table and a privacy protection routing protocol based on multi-party computation. Accomplishments in this dissertation are listed below:(1) This dissertation presents an exact top-k query algorithm based on filter and data distribution table with privacy protection(shorted for ETQFD). The algorithm does the query exactly and meanwhile uses conic section privacy function to prevent the disclosure of the real data and then to promise the security of nodes in network. In this proposal, each node in WSN uses data distribution table to reflect the distribution of its own data and keeps exact filter to just return data which is possibly to be the result of the query, so as to reduce the energy cost of network and prolong network lifetime. In addition, data of node is packaged with a privacy protection function based on conic section. The algorithm’s performance is examined with respect to a number of parameters using synthetic data sets.(2) In vehicular delay-tolerant networks, there exists a scenario in which some vehicles want to find parking-spaces, sometimes two vehicles will choose the same parking space, and then conflict appears. To solve this kind of problem, we propose a privacy protection protocol based on multi-party computation and a routing protocol based on angle and density. Privacy information of vehicles taking part in computing the common parking spaces will not be leaked out and the routing protocol performs well in transmission ratio and transmission delay for that we unify the direction of messages and choose those vehicles in the area with high vehicle density to be next hops.In summary, this thesis makes a deep research on the privacy preserving query in Wireless Sensor Network, and puts forward improvement algorithms, meanwhile, it analyzes and verifies performance of the proposed algorithms.