Efficient and traceable data sharing for the Internet of Things in smart cities

Data sharing in smart city applications supported by the Internet of Things (IoT) currently lacks privacy protection and accountability mechanisms for data leakage. When a data breach occurs, it is difficult for the data owner to trace the identity of the data leaker. To address this challenge, we propose an Efficient and Traceable IoT Data Sharing method (ETDS), which strives to solve the accountability problem of IoT data in multiparty sharing scenarios. The ETDS consists of a blockchain-based decentralized access control system and a commutative encryption and fingerprint system. ETDS not only implements data access authorization in a decentralized environment but also implements an efficient accountability mechanism for data leakages. Unlike other accountability solutions, the data accountability mechanism of ETDS is implemented in scenarios where the data and the applications are decoupled. This paper demonstrates the security and availability of ETDS through security analysis and an efficiency evaluation.