Enhancing interoperability and scalability in DiabeticChain: An integrative architecture using IPFS, Polygon, and HL7/FHIR

The global diabetes epidemic poses unprecedented challenges for secure, scalable, and interoperable management of patient health data. The exponential growth in both the volume and complexity of diabetic patient records overwhelms traditional centralized systems, which suffer from scalability bottlenecks, single point of failure, and data silos that hinder timely and coordinated care delivery. These limitations highlight the need for a robust, privacy-preserving, and standards-compliant architecture that empowers patients to control their data while enabling seamless exchange across heterogeneous healthcare systems. This paper presents an enhanced DiabeticChain architecture that holistically addresses these challenges through the integration of (i) Polygon, a layer-2 Ethereum scaling solution for high-throughput smart contract execution, (ii) IPFS for decentralized and tamper-resistant storage, (iii) HL7/FHIR standards for semantic interoperability, and (iv) zk-SNARK-enabled consent management for privacy-preserving access control. To ensure end-to-end confidentiality, the system employs hybrid encryption (AES-256-GCM + ABE/RSA) before persisting FHIR resources off-chain, with only content identifiers stored on-chain. The architecture is implemented and systematically evaluated using Hyperledger Caliper, executing 50-round workloads of both transactions and queries to identify throughput saturation points, latency trends, and resource utilization patterns. Results demonstrate near-linear scalability up to 240 TPS for state-changing operations and a query throughput ceiling of 687 TPS, with high reliability and sub-second latency across all workloads. These results confirm that the enhanced DiabeticChain achieves its design goals of interoperability, privacy, and scalability, offering a reproducible, standards-compliant, and auditable framework suitable for real-world deployment in patient-centric healthcare ecosystems.