BC-SSES: Secure Storage Extension and Sharing Method for Blockchain

With the rise of blockchain technology, data sharing between organizations is often established in a distributed blockchain ledger that is decentralized and tamperproof and has a low trust cost. However, traditional blockchain technology does not adequately support the on-chain storage of massive data, and all the on-chain stored data are completely open and transparent to participants; consequently, it is impossible to meet the user's needs for privacy protection. In this study, we designed a scalable data access control method for blockchains; this method extends the storage forms of the blockchain to support the chaining and sharing of large files, ensures that the traceable data in the chaining process cannot be tampered with, and introduces the attribute authority mechanism in peer nodes to improve the reliability and efficiency of attribute authorization. To verify the correctness and security of the method, we built a complete prototype system based on the Hyperledger Fabric license chain and performed rigorous evaluations on the indicators of physical resource consumption and performance using the Hyperledger Caliper evaluation model. The results showed that the proposed method achieved a good balance in terms of performance, safety, and resource consumption indicators.