基于区块链的医疗数据分类加密共享方案

Medical Data Classification Encryption Sharing Scheme Based on Blockchain

针对医疗数据共享时,存在共享数据多于需求数据,以及加密大量元数据会产生较大的计算开销问题,提出一种基于区块链的医疗数据分类加密共享方案,结合基于属性的加密和区块链实现对医疗数据的访问控制和数据共享。首先,按照基本信息、医疗科室、疾病类型将完整医疗数据分类划分为医疗元数据,对数据进行细粒度访问控制。其次,提出数据访问策略分类算法,将数据访问策略划分为属性加密策略和区块链访问策略,合并多个元数据的属性加密策略用以降低基于属性加密时构建访问结构树的计算开销;智能合约依据区块链访问策略对链上数据进行访问控制,并通过修改区块链策略实现权限撤销。最后,通过安全性分析和仿真实验表明该方案具有可行性和较高的效率。

When sharing medical data,the volume of shared data often exceeds the necessary amount,leading to significant computational overhead when encrypting a large number of metadata.This paper proposes a medical data classification encryption and sharing scheme based on blockchain,which integrates attribute-based encryption and blockchain to facilitate access control and data sharing of medical information.First,the entire medical dataset is classified into medical metadata according to the basic information,medical departments and disease types,enabling finegrained access control.Then,a data access strategy classification algorithm is proposed,which divides the data access strategy into attribute encryption strategy and blockchain access strategy.Multiple attribute encryption strategies are combined to reduce the computational cost of constructing the access structure tree.Smart contract controls the access of the data on the chain according to the blockchain access policy,and the authority is revoked by modifying the blockchain policy.Finally,the security analysis and simulation experiments validate the feasibility and efficiency of the proposed scheme.