Mitigating the Worst Parent Attack in RPL Based Internet of Things

The Low Power and Lossy Networks (LLNs) in the Internet of Things environment comprising constrained embedded devices have particular routing requirements that are well satisfied by the IPv6 Routing Protocol for Low Power and Lossy Networks (RPL). However, RPL is susceptible to several routing attacks. Worst Parent Attack (WPA) is an attack against RPL in which a malicious node intentionally chooses a sub-optimal path to the root node to forward its data packets. The result of which is sub-optimized performance and improper utilization of network resources of the IoT-LLNs. This paper proposes an efficient enhancement of the existing RPL protocol to make it resilient to the Worst Parent Attack. The proposed Enhanced RPL builds upon RPL and is henceforth named ERPL. The proposed ERPL achieves its objective by reducing the candidate set of parent nodes to an optimal parent set in the topological construction process. Thus, ERPL ensures that nodes choose a parent from a set of optimal nodes and makes IoT-LLNs resilient to WPA. We compare ERPL and RPL under normal and WPA scenarios. The comparison proves that ERPL, apart from providing security against the Worst Parent Attacks, also outperforms RPL in terms of energy consumption, packet delivery ratio, network convergence, and overall network overhead.