Low-Cost Tamper-Proof IoT Devices to Improve Data Origin Verification and Privacy in Blockchain-Based Energy Consumption Records

Using sensor measurements and external data via the blockchain is the foundation of several investigated blockchain applications. These applications aim to take advantage of some of the key features of blockchain technology. However, cost, security, authenticity, and privacy problems may hinder the creation of real-world decentralized systems involving individuals, especially if public blockchains are utilized. In this study, we describe a simple secure and privacy-preserving architecture for registering energy consumption into blockchain logs using low-cost Internet of Things devices, based on ESP32. The devices are programmed with a custom version of the Web3 library and protected from cloning and tampering, as well as any attempts to obtain the private keys. The proposed system allows the device to forward signed transactions that guarantee the data provenance. Privacy protection is achieved by public-key cryptography of measurement data on blockchain, and guaranteeing that it has no connection with addresses or other data that could identify an individual but only the device. Finally, computational overhead, transaction and setup costs, and transaction throughput are estimated to evaluate a widespread application in real-world conditions.