Privacy-Preserving and Collusion-aware k-NN Query Processing in Two-tiered Sensor Networks

With high expansibility of sensor electronic devices, wireless sensor networks have attracted more and more attention. The k nearest neighbors (k-NN) query has become a significant part of sensor networks due to its availability and convenience. However, it is an important but challenging problem to keep privacy and security while still maintaining low energy consumption. In this paper, we address this issue and propose PCKQ, a Privacy-preserving and Collusion-aware protocol for k-NN Query in two-tiered wireless sensor networks. Our solution consists of a novel k-NN query framework, a data encryption mechanism and comparison method. Extensive analysis and experimental results show the high performance of PCKQ in terms of energy efficiency, security and accountability requirements.