A Secure Sdn-Blockchain Architecture for Controlled Medical Data Access in IoT Networks

Abstract

The rapid proliferation of Internet of Things (IoT) devices in hospital environments introduces critical challenges in securing access control and auditing sensitive medical data, which traditional static and log-based network architectures fail to address. This paper proposes a secure architecture that integrates Software-Defined Networking (SDN) and blockchain (BC) to enable dynamic, fine-grained, and verifiable access to medical data. The SDN controller enforces adaptive policies across segmented network domains, while the BC layer provides tamper-proof auditability without exposing sensitive information. A policy-driven decision engine evaluates access requests based on contextual parameters. The solution is implemented and evaluated in a Mininet-based hospital network using ONOS, Kubernetes, and a Solana-based audit mechanism. Results show improved policy enforcement, reduced latency after initial flow setup, and enhanced audit transparency compared to a traditional VLAN-based architecture, demonstrating the effectiveness of SDN-BC integration in IoT healthcare systems.