HyMoTrust-RPL: A Trust-Aware Hybrid Routing Protocol for Mobile IoT Networks

Abstract

The IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) although widely accepted for use in the Internet of Things (IoT) remains very much exposed to mobility-induced instability and routing attacks such as: blackhole and rank manipulation. These existing challenges have been addressed independently by existing extensions like HRP which is a mobility aware variant that stablizes changes and MSecTrust which is a trust-based protocol that strengthen security but none combine both dimensions within a unified framework. This paper proposes HyMoTrust-RPL a hybrid, trust-aware extension that integrates HRP’s proactive–reactive routing with MSecTrust’s decentralized trust evaluation. HyMoTrust has been implemented in Python Simpy-based simulation framework and it introduces end-to-end trust propagation, adaptive trust thresholds, backup path caching, and a soft-fail fallback to maintain connectivity under attack. Comparative simulations with 30 mixed static and mobile nodes under combined blackhole and rank attacks show that HyMoTrust improves packet delivery ratio (PDR) by up to fourfold, reduces energy consumption by an order of magnitude, and doubles throughput relative to HRP, with only a modest increase in delay. These results demonstrate that integrating mobility and trust mechanisms yields a more resilient RPL, suitable for dynamic IoT environments such as smart cities and vehicular networks.