  In recent times researchers have found several security vulnerabilities in
the Routing Protocol for Low power and Lossy network (RPL), amongst which rank
attack is a predominant one causing detrimental effects on the network by
creating a fake topology. To address this concern, we propose a low-overhead
rank attack detection scheme for non-storing mode of RPL used in IoT to deal
with both increased and decreased rank attacks. Accordingly, we have modified
the RPL Destination Oriented Directed Acyclic Graph (DODAG) formation algorithm
to detect rank attacks during topology formation and maintenance. The
distributed module of the algorithm runs in all the participating nodes whereas
the centralized module runs in the sink. Unlike many existing schemes, instead
of sending additional control message, we make the scheme low-overhead by
simply modifying the DAO control message. Additionally, a lightweight Message
Authentication Code (HMAC-LOCHA) is used to verify the integrity and
authenticity of the control messages exchanged between nodes and the sink. The
correctness of the proposed scheme is established through a concrete proof
using multiple test case scenarios. Finally, the performance of the proposed
scheme is evaluated both theoretically and through simulation in Contiki-based
Cooja simulator. Theoretical evaluation proves the energy efficiency of the
scheme. Simulation results show that our scheme outperforms over a
state-of-the-art rank attack detection scheme in terms of detection accuracy,
false positive or negative rate and energy consumption while also keeping
acceptable network performance such as improved detection latency and at par
packet delivery ratio.
