Secure and Verifiable Top-k Query in Two-Tiered Sensor Networks

Abstract

Two-tiered sensor networks have been widely adopted since they offer good scalability, efficient power usage and storage saving. Storage nodes, responsible for storing data from nearby sensors and answering queries from the sink, however, are attractive to attackers. A compromised storage node would leak sensitive data to attackers and return forged or incomplete query results to the sink. In this paper, we propose SVTQ, a Secure and Verifiable Top-k Query protocol that preserves both data confidentiality and integrity of query results. To preserve data confidentiality, we propose prime aggregation whereby storage nodes can process top-k queries precisely without knowing actual data values. To preserve integrity of query results, we further propose a novel scheme called differential chain that allows the sink to verify any forged or incomplete result. Both theoretical analysis and experimental results on the real-world data set confirm the effectiveness and efficiency of SVTQ protocol.