Blockchain-based cloud storage system with CP-ABE-based access control and revocation process

Cloud system provides an on-demand and low-cost computing and storing model. Many organizations and individual end-users are using cloud storage services to back up their crucial data. However, this storage utility suffers from various threats and security issues. Before outsourcing the data to the cloud server, some data security measures should be imposed to ensure security. The blockchain is an advanced technology that stores data in a distributed manner and provides a more secure environment. Therefore, we propose a blockchain-based framework with the Ciphertext Policy Attribute-based Encryption algorithm to provide access control and user revocation methods in the cloud storage system to resolve the above issues. Our scheme offers three main features to provide a secure environment. First, a java-based blockchain network is designed to register data owners and attribute authority using a key generation algorithm. Second, the data owners and attribute authorities store the public information in the blockchain structure, set access policies, and generate the user's secret key to resolve key escrow problems. Third, the immediate attribute modification is deployed to attain fine-grained access control with the user revocation process. The experimental results, analysis, and performance evaluation show that our scheme provides a feasible and reliable environment.