FGDB-MLPP: A fine-grained data-sharing scheme with blockchain based on multi-level privacy protection

In the era of 5G, billions of terminal devices achieve global interconnection and intercommunication, which leads to the generation of massive data. However, the existing cloud-based data-sharing mechanism faces challenges such as sensitive information leakage and data islands, which makes it difficult to achieve secure sharing across domains. In this paper, the authors propose a fine-grained data-sharing scheme based on blockchain and ciphertext policy attribute-based encryption, and design a verifiable outsourced computation method to reduce the computational pressure of end users. Second, the authors comprehensively consider the user's identity privacy and transaction privacy, and propose a multi-level privacy protection method based on ring signature and garbled bloom filter, which enhance the user's data privacy and availability, and prevent the traceability of requests. Finally, the authors design a set of interconnected smart contracts, and verify that their scheme can achieve secure and efficient data sharing through security analysis and performance testing. (1) A blockchain-based efficient data-sharing scheme is proposed, which employs the ciphertext policy attribute-based encryption algorithm to enable fine-grained sharing of data resources.(2) An anonymous identity authentication method based on ring signatures is proposed, which can effectively protect the user's identity privacy and transaction privacy.(3) Security analysis shows that the authors' scheme satisfies data confidentiality and anti-collusion attack, which can effectively protect identity privacy and transaction privacy. image