A Decentralized Blockchain-Based Platform for Secure Data Sharing in Cloud Storage Model

In recent years, cloud-based storage systems have played a crucial role in facilitating secure user communication. These systems enable businesses to gain convenient, on-demand network access to a shared pool of configurable computing resources and effectively reduce overall costs by outsourcing the necessary services. However, it introduces new security challenges in management and control, specifically related to secure services and data sharing in distributed databases. In addition, until now there are still limits, especially in terms of security, access control, and centralization problems. In this paper, we propose a secure distributed cloud file storage and sharing system based on the Ethereum blockchain and Interplanetary File System (IPFS) to address these shortcomings. First, we encrypt data with the AES symmetric algorithm before storing it on IPFS, to resolve data leaks and tampering in centralized cloud storage. Second, we implement a distributed and reliable access control policy by sharing the list of authorized users on the blockchain network as a smart contract. We use the ECC algorithm to share encryption keys between data owners and users. Our solution is designed to ensure secure communication, data storage reliability over IPFS, and data controllability without relying on a centralized cloud storage architecture. Finally, the proposed scheme was tested and evaluated on the Ethereum test network. Performance evaluation shows that our system provides a feasible and reliable environment and could effectively resist both isolated and collaborative attackers, as well as untrusted cloud servers.