(ICIOT 2022) Exploration of Thermoelectric Energy Harvesting for Secure, TLS-based Industrial IoT Nodes

Frederik Lauer, Maximilian Schöffel, Carl Christian Rheinländer and Norbert Wehn (University of Kaiserslautern, Germany)

Security is one of the biggest challenges, particularly in the Industrial IoT and in critical infrastructures. Complex cryptographic computations are in contrast to the low energy budget of the devices, especially when independence from the power grid is required, as it is the case with retrofitted sensor nodes. Energy harvesting offers a promising alternative but tightens the energy constraints of the application further. In this work, we investigate how IoT edge devices can be powered by thermal energy harvesting and concurrently meet the stringent TLS-based security requirements. We analyze a thermoelectric generator system at its lowest power output region and evaluate different energy storage technologies in a representative IoT architecture. Our results show that temperature gradients as low as 1 K are sufficient to enable secure connections every 20 min in a representative Industrial IoT application.