Decentralized Secure Storage and Data Sharing Model via Blockchain

The rapid growth of the Internet of Things has ledto an unprecedented increase in the volume of data generatedand shared across various devices and platforms. Consequently, the surge in data generation and sharing has heightened theneed for robust security measures, as these interconnected IoT devices are often susceptible to a multitude of cyber threats, ranging from unauthorized access and data breaches to malicioustampering and disruption of critical services. This paper presentsIoTChain, an advanced decentralized framework for secure storage and data sharing in Internet of Things (IoT) ecosys-tems. The proposed model ensures end-to-end encryption and precise, fine-grained access control through a role-based access control (R-BAC) system. IoTChain incorporates the Ethereum blockchain as a trusted, decentralized access management layer, leveraging smart contracts to guarantee secure and transparent access rights. By integrating Ethereum with the InterPlanetary File System (IPFS), the model provides decentralized, scalable, and fault-tolerant storage. Security is reinforced using Advanced Encryption Standard (AES) for data encryption, while secure keyexchange is achieved through the elliptic curve Diffie-Hellman (ECDH) protocol. To optimize efficiency, the traditional proof- of-work (PoW) consensus mechanism is replaced with proof- of-authority (PoA), significantly reducing transaction costs and boosting throughput.