A Blockchain-Assisted Electronic Medical Records by Using Proxy Reencryption and Multisignature

Electronic medical records (EMR) have been commonly used in medical institutions in recent years. In particular, the combination of EMR and the cloud server has significantly improved the work efficiency and therapeutic level of the hospital. It also raises some security concerns, e.g., the information leaks. Blockchain has features including decentralization, traceability, openness, and tamper resistance. Therefore, the technology may be used to overcome the above flaws. In this paper, we introduce a new blockchain-assisted EMR in the cloud environment by using proxy reencryption and sequential multisignature. Firstly, blockchain makes the scheme have high-security performance without a trusty center. Secondly, we use proxy reencryption to protect personal medical data while helping doctors to access patients’ historical medical records. Moreover, the doctors have used a sequential multisignature, which is practical and can effectively improve security performance. The analysis results show that the proposed scheme can satisfy various security features of EMR and has an ideal computational and communication cost. Finally, the scheme is implemented to show its performance.