A Flexible and Efficient Privacy-Preserving Range Query Scheme for Blockchain-Enhanced IoT

With the increasing deployment of Internet of Things (IoT) devices in recent years, blockchain-enhanced IoT has become a new research hotspot. Due to its excellent openness, traceability and other performance, it has immensely promoted the development of this field. However, the traditional “edge-fog-cloud” three-tier architecture model for IoT still faces the threats of privacy disclosure, collusion attack, and low efficiency. To solve these problems, in this article, we creatively design a new consortium blockchain-enhanced IoT architecture, which can enable the permissioned users or participants to enjoy high-quality data services with the assistance of consortium blockchain by taking advantage of its high credibility. Based on this architecture, we propose a novel consortium blockchain-based privacy-preserving range query scheme in the decentralized IoT system, named CBCPRQ. This scheme combines consortium blockchain and inner product function encryption technology to realize flexible, safe, and batch range query of data service in edge computing. Analysis of security shows that our proposed scheme can not only protect the privacy but also perfectly resist the collusion query inference attack and the replay attack. Extensive performance evaluation is implemented by using Hyperledger Fabric platform and demonstrates that our scheme is efficient, scalable, and flexible.