Blockchain-Enabled Mitigation Strategies for Distributed Denial of Service Attacks in IoT Sensor Networks: An Experimental Approach

Information security has emerged as a crucial consideration over the past decade due to escalating cyber security threats, with Internet of Things (IoT) security gaining particular attention due to its role in data communication across various industries. However, IoT devices, typically low-powered, are susceptible to cyber threats. Conversely, blockchain has emerged as a robust solution to secure these devices due to its decentralised nature. Nevertheless, the fusion of blockchain and IoT technologies is challenging due to performance bottlenecks, network scalability limitations, and blockchain-specific security vulnerabilities. Blockchain, on the other hand, is a recently emerged information security solution that has great potential to secure low-powered IoT devices. This study aims to identify blockchain-specific vulnerabilities through changes in network behaviour, addressing a significant research gap and aiming to mitigate future cybersecurity threats. Integrating blockchain and IoT technologies presents challenges, including performance bottlenecks, network scalability issues, and unique security vulnerabilities. This paper analyses potential security weaknesses in blockchain and their impact on network operations. We developed a real IoT test system utilising three prevalent blockchain applications to conduct experiments. The results indicate that Distributed Denial of Service (DDoS) attacks on low-powered, blockchain-enabled IoT sensor networks cause measurable anomalies in network and device performance, specifically: (1) an average increase in CPU core usage to 34.32%, (2) a reduction in hash rates by up to 66%, (3) an increase in batch timeout by up to 14.28%, and (4) an increase in block latency by up to 11.1%. These findings suggest potential strategies to counter future DDoS attacks on IoT networks.