Authors: Zijian Bao, Debiao He, Huaqun Wang, Min Luo, Cong Peng

 

Title: A Group Signature Scheme with Selective Linkability and Traceability for Blockchain-Based Data Sharing Systems in E-health Services

 

Abstract: Recently, with the rapid improvement of e-health technology, a large amount of precious medical data has been accumulated in different entities, such as hospitals, clinics, and medical institutions, promoting the development of data sharing in e-health services. However, most of them lacks fine-grained functionalities: selective linkability and traceability, which are critical in an e-health environment. Furthermore, we observe that existing schemes mostly rely on centralized storage centers, which will lead to a single point of failure and privacy disclosure. In this paper, we first construct a group signature scheme SLTGS suitable for a data sharing environment. It supports selectively linking two different message-signature pairs to the same signer. Further, it provides an algorithm to trace the signer. Then, based on the SLTGS scheme, we leverage distributed technology (i.e., InterPlanetary file system and blockchain) and attribute-based encryption to propose a distributed data sharing scheme. We claim that our scheme meets anonymity, accountability, linkability, traceability, fine-grained and efficient access control, and distributed storage. Moreover, the proposed data sharing scheme yields a practical performance making it suitable for e-health applications.