A Blockchain-Based Searchable Encryption Scheme for Efficient Data Sharing
Shu-Sheng Ge, Shuming Xiong, Pengchao Chen, Qingqing Xie · 2023
Data sharing is being paid more and more attention with networked data growing. However, the existing solutions suffer from low search efficiency when there is a large amount of data. Furthermore, the shared data may also be accessed by other people without authorization, causing security threats of privacy leakage. To solve these problems, we propose a blockchain-based efficient data sharing scheme with searchable encryption called BEDShare. In our scheme, encrypted shared data are stored in the Interplanetary File System (IPFS), and the corresponding indexes are stored in a consortium chain possessed by data users. Based on the discrete logarithm problem, we design an access authorization protocol, making it available to query the relevant data by generating the search trapdoor. We also optimize the searchable encryption for the problem of low search efficiency that occurs when the number of indexes is large to improve the efficiency of the scheme. In addition, we present an authorization protocol without a trusted authority. With the authorization operation, the data owner can decide who is allowed to access the shared data. Thus, BEDShare is privacy-protected and fully decentralized. Finally, we implement a prototype of the construction scheme, and the simulation results shows that the efficiency and practicability of the proposed scheme are encouraging.