SFDB-MLPP: A Secure and Fine-Grained Data Sharing Scheme with Blockchain Based on Multi-Level Privacy Protection

Abstract As the network communication and service capabilities rapidly improve in the 5G era, 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. The emerging Blockchain technology can achieve secure transmission among unfamiliar nodes without relying on trusted third parties, which can provide a solution for data sharing in the cloud environment of 5G mobile internet. In this paper, we propose a fine-grained and efficient data sharing scheme based on Blockchain and ciphertext policy attribute-based encryption (CP-ABE), and design a verifiable outsourced computation method to reduce the computational pressure of end users. Secondly, we 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 enhances the user’s data privacy and availability, and prevents the traceability of requests. Finally, we design a set of interconnected smart contracts, and verify that our scheme can achieve secure and efficient data sharing through security analysis and performance testing.