Secure Personal Health Records Sharing Based on Blockchain and IPFS

Abstract

Personal Health Records (PHR) system has attracted intensive attention due to its universal accessibility and low cost in economics. Because of high cost of storing data and access control, most PHR systems adopt centralized management, where an authoritative management center controls the entire system and PHR data is stored in a trusted third-party service provider. However, there are some disadvantages, such as fully trusting to a control center, suffering from a single point of failure, and data deleting. In this paper, we propose a novel distributed framework based on blockchain and IPFS (Inter Planetary File System), and a suite of mechanisms for data access control to PHR data. Smart Contracts are designed on the blockchain, and all data operations are treated as transactions. The symmetric cryptographic algorithm is used to encrypt the PHR data, and then all encrypted data is stored on IPFS nodes securely in distributed environment. The ciphertext-policy attribute-based encryption (CP-ABE) is used to encrypt the symmetric secret keys, and the corresponding ciphertext is stored and published in IPNS (Inter Planetary Name Space), so as to achieve fine-grained access control. Analytical and experimental results are presented, which show that our framework has ability to provide authenticity, confidentiality, fine-grained access control, forward secrecy, and traceability simultaneously.