MedZKChain: Attribute-Based, Privacy-Preserving Device Verification and Access Authorization for Healthcare Using Blockchain and zk-SNARKs

The collection and application of health care data are crucial for advancing research and improving healthcare. However, privacy and security concerns, particularly with sensitive data, pose significant challenges. Traditional identity-based verification systems, which rely on centralized servers, struggle in medical contexts due to regional data management complexities and the vulnerabilities of centralized models. In this paper, we propose MedZKChain, a privacy-preserving health care device verification system designed to address these challenges. By combining blockchain technology with zero-knowledge proofs, MedZKChain enables decentralized device attribute verification while ensuring data integrity and privacy. The system provides a solution for managing the access of medical records in different regions. MedZKChain leverages decentralized storage to reduce blockchain burden and uses zero-knowledge proofs to allow for secure verification and access authorization without revealing sensitive data. Experimental results demonstrate that, when authorized querying 1,500 patient data records, the proof size in MedZKChain remains less than 100 KB, the proving time is less than 3 seconds, and the verification time is below 0.8 seconds. These results highlight the system efficiency, scalability, and its effectiveness in enabling decentralized, verifiable.