Cloud-Based Blockchains for Secure and Reliable Big Data Storage Service in Healthcare Systems

Due to regulations and policies enacted to protect patients' privacy, electronic health records (EHRs) must be kept as sensitive information in a secure and reliable manner. Maintaining EHRs by hospitals and safely sharing them with others have proved to be challenging tasks. In this paper, we introduce a cloud-based blockchain (CBC) approach to achieving data accessibility, redundancy, and security for storing and sharing EHRs. A lightweight CBC, called lite blockchain (LBC), is designed to store EHRs' metadata and text-based information locally. Our approach allows for big data to be safely stored in CBCs, and for information to be efficiently retrieved via LBCs. To restrict and grant access of the data to authorized participants only, we present our data security mechanism along with role-based access control policies. The experimental results show that our cloud-based blockchain approach is feasible and efficient for accessing and sharing EHRs stored both locally and in clouds.