The Data Sharing Scheme based on Blockchain

Data sharing is a vital method for data intensive and cooperative work-based applications. A central database system, which collects and stores data generated from different parties and provides open access, can not only save costs on infrastructures, but also provide consistent and uptodate data for all the participants. However, privacy and security issues also emerge especially when the shared data is highly sensitive, such as electronic medical records (EMRs). In this paper, we propose a new data sharing scheme with access control based on CP-ABE, searchable encryption, and blockchain. We realize two main goals in our scheme. First, data owners can share their data with multiple users who satisfy the access policy rather than just a single user. Second, the difficulty of the ciphertext query is overcome by means of searchable encryption technology. Most importantly, data owners do not need to interact with the data querier in the process of sharing. Both theoretical analysis and practical experiments show that the proposed scheme is secure and efficient.