The paradox between the dramatic development of medical data privacy demand and years of bureaucratic regulation has slowed innovation for electronic medical records (EMRs). We are at a historical point for such innovation to prompt patients data autonomy. In this paper, we propose GuardHealth: an efficient, secure and decentralized Blockchain system for data privacy preserving and sharing. GuardHealth manages confidentiality, authentication, data preserving and data sharing when handling sensitive information. We exploit consortium Blockchain and smart contract to achieve secure data storage and sharing, which prevents data sharing without permission. A trust model is utilized for precisely managing trust of users with the implementation of the state-of-art Graph Neural Network (GNN) for malicious node detection. Security analysis and experiment results show that the proposed scheme is applicable for smart healthcare system.

医疗数据隐私需求的急剧发展与多年官僚监管之间的自相矛盾，减缓了电子医疗记录（EMR）的创新。我们在这种创新方面具有历史意义，可以促进患者数据自治。在本文中，我们提出了GuardHealth：一种用于数据隐私保护和共享的高效，安全和分散的区块链系统。在处理敏感信息时，GuardHealth管理机密性，身份验证，数据保留和数据共享。我们利用联盟区块链和智能合约来实现安全的数据存储和共享，从而防止未经许可的数据共享。信任模型用于通过实施用于恶意节点检测的最新图形神经网络（GNN）来精确管理用户的信任。