Blockchain based efficient tamper-proof EHR storage for decentralized cloud-assisted storage

In recent years, the rapid and wide-ranging implementation of a cloud-based electronic healthcare record (EHR) storage system has shown significant advantages in effectively managing EHR for healthcare organizations and patients. However, in the cloud-based EHR storage model, the patients no longer have direct control of their EHR, whereas healthcare organizations may access the outsourced EHR whenever necessary. It may always cause severe security issues, specifically when healthcare organizations collude with the cloud service provider (CSP) to conceal any medical malpractice. Therefore, to deal with these significant concerns, we have introduced a novel blockchain based efficient tamper-proof model for EHR storage in decentralized InterPlanetary File System (IPFS) storage in the cloud - “TAC-EHR”. The key idea of the model is that every operation involves outsourcing EHRs and integrating these EHRs into a transaction on the public blockchain provides computationally unforgeability to the outsourced EHRs. Moreover, the proposed EHR storage model can also manage batch outsourcing, i.e., numerous EHR outsourcing for multiple patients by multiple doctors simultaneously, in an effective manner. The experimental and security analysis demonstrates that the proposed blockchain based cloud-assisted EHR storage model efficiently assures intractability computationally and outperforms the existing models in terms of computational and communication overhead.