IEEE ACCESS, cilt.12, ss.90952-90970, 2024 (SCI-Expanded)
Many Industrial Internet of Things (IIoT) applications require wireless networks with low power consumption, low latency, and secure communication. The IPv6 over the TSCH mode of IEEE 802.15.4e (IETF 6TiSCH) standard has been created to fulfill these requirements and provide reliable and efficient communication, specifically in industrial environments. A reliable authentication process is the first step towards the ensuring privacy and security of a wireless IoT network. The IETF Constrained Join Protocol (CoJP) is the standard centralized authentication protocol developed by the IETF 6TiSCH Working Group which is used to manage the node bootstrapping processes through a centralized entity named as Join Registrar/Coordinator (JRC). This process requires the joining nodes to be authenticated via the JRC entity. Centralized authentication within 6TiSCH networks exhibits scalability limitations beyond small-to-medium deployments, necessitating alternative approaches for applications requiring large number of deployed nodes. Using a distributed approach where JRC role is distributed among the nodes within the network can help to mitigate this drawback. In this paper, a node placement method for a decentralized authentication process is introduced to address the scalability challenges of the centralized authentication process in 6TiSCH networks where a heuristic solution that can optimise Proxy-JRC placement has been proposed. Experimental results with 2,3 and 4 number of Proxy-JRC nodes placed by the proposed approach show up to 25% improvement in terms of key update time and up to 22% in terms of power consumption. These results highlight the benefits of employing a distributed key update mechanism to meet low power consumption, low latency, and secure communication requirements in large-scale 6TiSCH networks.