Secure electronic medical records sharing scheme based on blockchain by using proxy re-encryption

The sharing of electronic medical records (EMRs) is of immense value for disease research and epidemic prevention. It has received considerable attention from researchers. EMR sharing and management which based on blockchain have demonstrated remarkable achievement. Nevertheless, there remain certain obstacles that necessitate attention and resolution. Most blockchain-based eHealth systems store EMRs on outsourcing companies. The outsourcing companies may leak electronic medical records. Moreover, patients cannot decide who can access their electronic medical records and lose control of their EMR completely. To solve these problems, we propose a patient-centered EMR sharing and management scheme based on blockchain with proxy re-encryption algorithm to protect the interests of the patient and use smart contracts to achieve patients control on their electronic medical records. Moreover, a decentralized proxy that re-encrypts the electronic medical records is adopted to improve the security and availability of our system. Furthermore, we use an architecture to compute the hash root with chameleon hash to implement additional features such as electronic medical record modification, emergency access, and access revocation. To evaluate our scheme, our scheme is deployed on Hyperledger Fabric. The results which published by Hyperledger Caliper show the successful performance of our scheme in achieving security and privacy requirements.