This article presents a blockchain-based solution to enhance data security and privacy in the Internet of Things (IoT). The authors propose a blockchain as a service (BaaS) application based on Hyperledger Fabric v2.x to address the security and privacy challenges associated with IoT. A new architecture is introduced to enable this integration, and its performance is analyzed in real-world scenarios. The system includes a four-layer architecture that connects IoT devices with Hyperledger Fabric, a private and permissioned blockchain, to provide a secure, decentralized ledger for data transfers. The architecture includes a physical layer for data collection, a network layer for data transmission, a middle layer for data processing and storage, and an application layer for data visualization and firmware management. The system uses Kafka as a real-time data streaming pipeline to transfer data to the blockchain, and IPFS for off-chain storage. The data is encrypted using public and private keys to ensure privacy and security. The system also includes a data structure that allows for efficient management of data storage and transaction processing. The authors conducted experiments to evaluate the performance of the system, showing that it can handle a high volume of transactions with low latency and high throughput. The results indicate that the proposed architecture can effectively address the security and privacy challenges of IoT, providing a scalable and efficient solution for data storage and transmission. The study highlights the potential of blockchain technology in enhancing the security and privacy of IoT systems, and suggests that further research is needed to optimize the system for different applications.This article presents a blockchain-based solution to enhance data security and privacy in the Internet of Things (IoT). The authors propose a blockchain as a service (BaaS) application based on Hyperledger Fabric v2.x to address the security and privacy challenges associated with IoT. A new architecture is introduced to enable this integration, and its performance is analyzed in real-world scenarios. The system includes a four-layer architecture that connects IoT devices with Hyperledger Fabric, a private and permissioned blockchain, to provide a secure, decentralized ledger for data transfers. The architecture includes a physical layer for data collection, a network layer for data transmission, a middle layer for data processing and storage, and an application layer for data visualization and firmware management. The system uses Kafka as a real-time data streaming pipeline to transfer data to the blockchain, and IPFS for off-chain storage. The data is encrypted using public and private keys to ensure privacy and security. The system also includes a data structure that allows for efficient management of data storage and transaction processing. The authors conducted experiments to evaluate the performance of the system, showing that it can handle a high volume of transactions with low latency and high throughput. The results indicate that the proposed architecture can effectively address the security and privacy challenges of IoT, providing a scalable and efficient solution for data storage and transmission. The study highlights the potential of blockchain technology in enhancing the security and privacy of IoT systems, and suggests that further research is needed to optimize the system for different applications.