Deletion and Recovery Scheme of Electronic Health Records Based on Medical Certificate Blockchain

The trusted sharing of Electronic Health Records (EHRs) can realize the efficient use of medical data resources. Generally speaking, EHRs are widely used in blockchain-based medical data platforms. EHRs are valuable private assets of patients, and the ownership belongs to patients. While recent research has shown that patients can freely and effectively delete the EHRs stored in hospitals, it does not address the challenge of record sharing when patients revisit doctors. In order to solve this problem, this paper proposes a deletion and recovery scheme of EHRs based on Medical Certificate Blockchain. This paper uses cross-chain technology to connect the Medical Certificate Blockchain and the Hospital Blockchain to realize the recovery of deleted EHRs. At the same time, this paper uses the Medical Certificate Blockchain and the InterPlanetary File System (IPFS) to store Personal Health Records, which are generated by patients visiting different medical institutions. In addition, this paper also combines digital watermarking technology to ensure the authenticity of the restored electronic medical records. Under the combined effect of blockchain technology and digital watermarking, our proposal will not be affected by any other rights throughout the process. System analysis and security analysis illustrate the completeness and feasibility of the scheme.