本项目以两层传感器网络中的存储节点易受攻击的特点为研究背景，提出一种新的面向隐私保护的安全KNN查询机制。依据两层传感器网络的拓扑特点，重点研究网络中的隐私保护、查询结果完整性认证、容忍节点失效等安全KNN查询问题，并提出相关的研究内容和技术方案和路线。针对妥协存储节点存在泄露敏感数据的问题，提出基于区间划分编码算法的隐私保护方法，由此保证存储节点上的数据安全且能支持K-NN查询；针对妥协存储节点返回不完整查询结果的问题，提出了一种基于Voronoi图的查询结果完整性验证机制，解决查询结果的完整性验证问题。针对传感器节点因失效而产生的虚警现象，建立节点信誉度评价模型，提出低虚警的安全查询算法。最后形成能支持隐私保护与查询结果验证的低虚假的安全KNN查询机制。项目将采用仿真和实验相结合的方法对提出的算法和机制进行评价。该课题的研究,将有助于推动两层结构传感器网络的应用,促进传感器网络的发展。

Two-tiered wireless sensor networks offer good scalability, efficient power usage, and space saving. However, storage nodes are more attractive to attackers than sensors because they store sensor collected data and processing sink issued queries. A compromised storage node not only reveals sensor collected data, but also may reply incomplete or wrong query results. In this project, we propose a new privacy preserving secure k-NN query mechanism. According to the topological characteristics of two-tiered wireless sensor networks, we focus on safety k-NN query issues such as privacy preserving, query results integrality verification and tolerance node failure; and propose relevant research and technology solutions and directions. Aimed at the existing sensitive data leakage problem in compromised storage node, we propose a privacy protection method based on interval division encoding Algorithm, thereby ensuring data security on the storage nodes and supporting k-NN query. Aimed at the problem of returning incomplete query results in compromised storage node, propose a query results integrality verification mechanism based on Voronoi diagram to solve the query results integrality verification problem. Aimed at the arising false-alarm phenomenon due to sensor nodes failure, we establish credibility evaluation model of nodes, and propose a low false-alarm security query algorithm. Finally form a low false security k-NN query mechanism that can support privacy protection and the query results verification. In the project, we will use combination methods of simulation and experimental to evaluate the proposed algorithms and mechanisms. The research on this project will contribute to promote the application of two-tiered structure wireless sensor networks and the development of sensor network.