Security-Aware Node Replacements and Incremental Updates in Industrial IoT Platforms

IIoT is the industrial tier of the Internet of Things initiative characterized by stringent security requirements, high sensor fault rates, and frequent mission-critical software updates. In this work, we propose the design and implementation of two security-aware protocols for node replacements and incremental software updates in IIoT. The node replacement protocol ensures the legitimacy of newly added replacement sensors by coordinating an efficient key management procedure to refresh their cryptographic keying material without the need of resource-intensive public-key cryptographic techniques. This is done by leveraging private secret sharing protocols and relying on the already established security associations between the IoT gateway and neighboring sensor nodes. The node update protocol supports multi-component software updates on the IIoT sensors and ensures their authenticity using probabilistic set membership data structures. This results in major reductions in network traffic overhead and protocol convergence times compared to traditional integrity enforcement approaches at the expense of minimal false positives probability. Moreover, the node update protocol realizes an incremental component loading and integrity verification mechanism on the IIoT sensors that lessens their storage requirements and avoids any superfluous operation intermission. A prototype implementation of the two proposed protocols demonstrates their feasibility in a real IoT network and exhibits high savings in convergence time and network traffic overhead.