BECAAC: A Blockchain and Edge Computing-Assisted Access Control Scheme for Medical Data Sharing

Securing the sharing of medical data has become a critical issue in the field of medical informatics. Although existing Internet of Medical Things-based medical data sharing systems prioritize data security, anonymity, and operational efficiency during transmission, they still exhibit significant shortcomings in preventing unauthorized access and establishing effective accountability mechanisms. Therefore, a solution is urgently needed to ensure fine-grained access control and accountability during data sharing. This article proposes a novel data sharing system, BECAAC, which is based on blockchain and edge computing. By employing an edge computing-assisted, contract-based access control strategy and proxy re-encryption technology, the system reduces the computational overhead on hospitals and edge nodes while ensuring that only authorized entities can access medical data. Additionally, a blockchain-based verifiable and traceable anonymization scheme has been developed, utilizing group signature technology to ensure patient identity anonymity. By integrating the decentralization, transparency, and immutability features of a consortium blockchain, this approach enhances accountability for malicious behavior. Experiments conducted using Hyperledger Fabric and EdgeCloudSim were performed to evaluate the performance and simulate the proposed solution. The results indicate that BECAAC effectively meets the requirements of real-world medical data sharing environments.