SBODS: A Secure Sharded Blockchain-based Online Diagnostic System During Pandemics

During pandemics,rapid and reliable diagnostic testing is essential for timely treatment and disease containment. However, existing diagnostic methods, whether centralized testing facilities or home kits, face limitations in scalability, data integrity, and privacy. In this paper, we propose SBODS, the first secure and scalable Sharded Blockchain-based Online Diagnostic System. SBODS enables remote collection of test requests, ensures privacy-preserving diagnosis and reporting, and facilitates authorized data sharing for public health research. To address critical challenges such as test result manipulation, denial-of-service (DoS) attacks, and IP traceability, we integrate a robust security architecture, including group signatures and a novel Blockchain Onion Routing Network (BORN). Our performance evaluation demonstrates that SBODS can report test results for up to 2 million patients within 15 minutes, with 100% detection accuracy for data manipulation attempts. These results highlight SBODS as a viable framework for secure, decentralized pandemic response.