Benchmarking Constrained IoT Devices in Blockchain-Based Agri-Food Traceability Applications

The adoption of blockchain technology combined with the Internet of Things in agri-food traceability scenarios is gaining momentum in terms of research and development. The intrinsic capability of blockchain to provide immutable and tamper-proof records is the perfect match for IoT systems comprising small sensing devices that can autonomously produce information across the entire process. However, there has been little discussion on the impact that blockchain has on the constrained sensing IoT devices in terms of their limited resources. These devices are the core of modern IoT systems providing the sensing layer for the entire application. In this paper, we focus on assessing the impact that a blockchain traceability system may have on such constrained sensing devices. To this end, we benchmark six IoT hardware platforms in terms of space and memory usage, processing time, and energy consumption as elements of a trustless event-based traceability application over two blockchain networks, namely Ethereum, as an example of permissionless network, and Hyperledger Sawtooth, as a permissioned counterpart. Our results and analysis provide an empirical reference for the study and development of blockchain-based traceability systems using constrained sensing IoT devices.