A Blockchain-Based Medical Data Security Sharing Scheme Supporting Single-Factor Combined Authentication and Identity Privacy Protection

In the context of the rapid development of digital healthcare, achieving secure and verifiable medical data sharing has become a significant challenge. We propose a blockchain-based medical data sharing scheme that incorporates single-factor combined authentication and identity traceability, leveraging the transparency and immutability of blockchain. In this scheme, we propose a novel proxy re-encryption scheme that ensures user identity privacy, supports secure identity verification, and enables identity traceability under necessary conditions, as well as the secure distribution of keys. Additionally, our scheme uses groups to isolate business and resources, enhancing its flexibility and scalability. Through security analysis and experimental evaluation, we demonstrate that our scheme effectively resists chosen plaintext attacks while maintaining high efficiency and practicality.