Privacy-Preserving Healthcare Architecture Using Blockchain

Since the introduction of Internet of Things (IoT), e-health has become one of the main research topics. Due to the sensitivity of patient data, preserving the privacy of patients appears to be challenging. In healthcare applications, patient data are usually stored in the cloud, which makes it difficult for the users to have enough control over their data. However, due to the General Data Protection Regulation (GDPR), it is the data subject's right to know where and how his data has been stored, who can access his data and to what extent. In this paper, we propose a blockchain-based architecture for e-health applications which provides an efficient privacy-preserving access control mechanism. We take advantage of Blockchain (BC) special features, i.e., immutability and anonymity of users, while modifying the classic blockchain structure in order to overcome its challenges in IoT applications (i.e., low throughput, high overhead and latency). To this end, we cluster the miners of BC, store and process data at the nearest cluster to the patient. While our proposal is a work in progress, we provide a security analysis of our proposed architecture.