Secure cross‐chain transactions for medical data sharing in blockchain‐based Internet of Medical Things

Blockchain technology has greatly promoted the development of the Internet of Medical Things (IoMT) from a centralized form to a distributed form. However, with many independent blockchain‐based IoMT (BIoMT) systems being established by different institutions, these heterogeneous blockchain systems have created a new “data islands” problem. This paper proposes a multi‐chain fusion (MCF) multi‐party governance model based on relay chain technology. The MCF model helps establish cross‐chain interaction and communication among the multiple heterogeneous blockchain systems in different medical institutions through the cross‐chain gateway. Meanwhile, by utilizing the inter‐blockchain transfer protocol (IBTP), the MCF model takes responsibility for legitimacy verification and reliable routing of cross‐chain transactions, thus addressing the “data islands problem” inherent in traditional blockchain‐based medical systems. Then, an elliptic curve signature scheme is adopted to protect user privacy in cross‐chain transactions, which helps establish transaction verification for the MCF model in BIoMT systems. Finally, several experiments are carried out to prove the feasibility of the cross‐chain scheme and the security of the elliptic curve signature scheme, and the performance index of the cross‐chain system is evaluated. The performance results show that the MCF model can provide secure and efficient cross‐chain services for sharing medical data among heterogeneous BIoMT systems, thus addressing the “data islands problem” inherent in traditional blockchain‐based medical systems.