IbiboRPLChain II: A Blockchain-Enhanced Security Framework for Mitigating Routing Attacks in IoT-RPL Networks

The Internet of Things (IoT) continues to expand rapidly, with the Routing Protocol for Low-Power and Lossy Networks (RPL) serving as its core communication backbone. However, RPL remains vulnerable to a range of insider routing attacks such as the Version Number Attack (VNA) and Hello Flooding Attack (HFA), particularly in constrained IoT environments. In our previous work, IbiboRPLChain, we proposed a blockchain-based authentication mechanism to secure communication between routing and sensor nodes. This paper presents an evolved framework, IbiboRPLChain II, which integrates smart contracts, decentralised authentication nodes, and composite blockchain mechanisms to improve network resilience, scalability, and security. Our experiments, conducted using Cooja and Contiki OS, evaluate the system across multiple simulation seeds, demonstrating significant gains in Packet Delivery Ratio (PDR), energy efficiency, and delay mitigation. IbiboRPLChain II proves to be a robust solution for secure, lightweight, and scalable RPL-based IoT environments.