Towards a ledger-assisted architecture for secure query processing over distributed IoT data

Massive amount of IoT data poses unique challenges in centralized data management systems. Specifically, IoT data can originate from heterogeneous and distributed sources, and commonly regulations forbid data from different IoT stakeholders to be managed via central governance. To serve for IoT applications, recent proposals leverage distributed ledgers (e.g., blockchains) to function on top of distributed data storage with improved data interoperability. Unfortunately, most of them do not consider data security and privacy in the first place. Along with this transformative paradigm, in this paper, we propose a ledger-assisted architecture for secure distributed IoT data management. This architecture adapts searchable encryption to decentralized storage network to enable encrypted query processing. Meanwhile, it is designed to leverage the distributed ledger to harden both data and query integrity. To deal with continuously generated IoT data, we further devise an efficient secure data insertion protocol, and employ a recent variant of blockchain for users to validate updated query results in a scalable manner. Evaluations on Azure blockchain service confirm the practicality of our proposed architecture.