A Privacy-aware Electronic Medical Record Sharing Scheme based on Blockchain and Identity-based Cryptography

At present, blockchain has become the research focus in the field of medical information, especially in the storage and sharing of electronic medical records (EMR). With the advent of the era of big data, data privacy is particularly important for patients. However, in existing blockchain-based electronic medical record-sharing schemes, the transaction address in the blockchain is related, which poses the risk of privacy disclosure for patients. To to solve this problem, this paper proposes a privacy-aware sharing scheme of electronic medical records based on stealth address and smart contracts. We introduce a novel identity-based stealth address scheme that can ensure the privacy protection of patient data and avoid the complexity of certificate management under the PKI system. As far as we know, this is the first of its kind. The patient can control the data autonomously through a smart contract. We present the specific design process of the scheme and the security proof of the related algorithm. Compared with the existing schemes, the identity-based cryptosystem is more suitable for users. Meanwhile, the scheme uses the decentralized storage platform IPFS to store EMR data to avoid the limitations of centralized data storage.