A Novel Approach for Fast and Secure Data Transmission using Blockchain and IoT

The increase of Internet of Things devices has created new opportunities for collecting and processing data, but it also poses significant challenges in terms of management and security. Blockchain technology, originally introduced as the backbone of decentralized finance and payment systems, has evolved significantly since its inception. The immutability of stored data, achieved through cryptographic techniques and distributed consensus mechanisms, renders it particularly suitable for securing information across a network of interconnected devices, commonly referred to as nodes. Recent advancements, notably the introduction of Ethereum Blockchain, have broadened the scope of blockchain applications, popularizing concepts such as Smart Contracts and Non-Fungible Tokens, thus enabling greater flexibility for diverse use cases. This paper explores the utilization of a multi-layer blockchain-based architecture for temperature and humidity monitoring in a smart city environment. Building upon the foundational principles of blockchain technology, the proposed architecture leverages Hyperledger Fabric and Ethereum blockchains, providing a robust framework for IoT data management. A practical implementation with a Raspberry Pi device is presented, demonstrating the feasibility and effectiveness of the proposed solution.