Cloud-Assisted EHR Sharing With Security and Privacy Preservation via Consortium Blockchain

Abstract

The sharing of electronic health records (EHRs) has great positive significance for research of disease and doctors' diagnosis. In recent years, cloud-based electronic medical record sharing scheme has brought a lot of conveniences, but the centralization of cloud exposes threats inevitably to data security and privacy preservation. Blockchain technology can be seen as a promising solution to address these problems on account of its unique propertis of decentration, anonymity, unforgeability and verifiability. In this paper, we propose a blockchain based secure and privacy-preserving EHR sharing protocol. Data requester can search desired keyword from data provider to find relevant EHRs on the EHR consortium blockchain and get the re-encryption ciphertext from cloud server after getting the data owner's authorization. The scheme mainly uses searchable encryption and conditional proxy re-encryption to realize data security, privacy preservation, and access control. Furthermore, proof of authorization is designed as the consensus mechanism for consortium blockchain to guarantee system's availability. Security analysis demonstrates that the proposed protocol can achieve security goals. Besides, we emulate the cryptographic primitives and implement the proposed scheme on Ethereum platform. Performance evaluation shows that the proposed scheme has high computational efficiency.INDEX TERMS Electronic health records, data sharing, blockchain, data security, privacy preservation.

EdgeMediChain: A Hybrid Edge Blockchain-Based Framework for Health Data Exchange

“…Meanwhile, In order to ensure the validity of the shared EMRs within a system encompassing multiple non-trusted authorities, the authors in [49] introduced an attribute-based signature with blockchain that allows for patients the endorsement of a message without the disclosure of any further private details. In [50] the authors leveraged cloud-based storage with blockchain to manage the access to EMRs, meanwhile, security and privacy were preserved by utilizing proxy-based re-encryption and a designed proof of authorization (PoAuth) consensus mechanism. However, the proposed approach does not give full ownership of the records to the patients as these ones are still under the management of the healthcare providers and they are the ones responsible for uploading the EMRs to the cloud.…”

Privacy Preservation for On-Chain Data in the Permission less Blockchain using Symmetric Key Encryption and Smart Contract

“…But the model is not used for on-chain data privacy, it is used only for off-chain data privacy. A decentralized system is proposed in [8] for electronic health record. The system has five components: Data owner, Data provider, cloud server, blockchain, and data requester.…”

Design of Secure Authentication Protocol for Cloud-Assisted Telecare Medical Information System Using Blockchain

“…However, the public blockchain model [11] consumes an amount of computation cost because every node in the blockchain participates in a consensus process, and it can cause scalability problem. Therefore, numerous researchers utilized consortium blockchain for cloud-based medical environment [12], [13], [14]. In these schemes, the cloud server stores health data, and the related data such as a keyword, a hash, an address of the data are recorded on the blockchain.…”

“…These schemes utilize the cloud server for data storage and apply consortium blockchain so that data integrity and scalablilty is guaranteed. However, these schemes [12], [13], [14] do not deal with the mutual authentication and key agreement process. Therefore, we design a secure authentication protocol in a cloud-assisted TMIS.…”