Design and Development of a Lightweight Microcontroller-Assisted SDN Framework for Securing IoT Devices in Smart Homes

Abstract

Background: Consumer IoT devices are increasingly deployed in smart homes but are rarely designed with security as a priority, leaving them exposed to unauthorized access and volumetric attacks. Existing SDN-based defenses depend on Open Flow-compliant gateways that most home routers lack, while authentication and encryption remain immature for resource-constrained devices. Objective: This study presents a universal, Open Flow-independent framework that restricts unauthorized access to smart-home IoT devices. Methodology: A microcontroller is positioned between the home gateway and the wider network, monitoring flows and forwarding trace files to a cloud-based SDN controller; the controller returns updated policies through a northbound interface, and a fractional-selectivity value flags and blocks volume-based attacks. The framework was implemented in CloudSimSDN across one-to-six-switch topologies and benchmarked against the low-cost flow-based solution (LCFS) of Sivanathan et al. Key Results: The framework achieved a lower average data-plane load (4.01 Mbps) than the LCFS baseline (9.65 Mbps), with reduced IoT traffic, camera-module load, CPU, RAM, and energy consumption across all configurations. Main Contributions: (i) an Open Flow-independent, microcontroller-augmented SDN architecture; (ii) a fractional-selectivity mechanism for flow-level attack detection; (iii) a CloudSimSDN evaluation benchmarked against an established baseline. Conclusion: A lightweight microcontroller paired with SDN can restrict unauthorized IoT access at lower resource cost than Open Flow-dependent alternatives, offering a practical route to scalable smart-home security.