Research on Blockchain Technology for Cloud Security focuses on leveraging the decentralized, tamper-resistant, and transparent features of blockchain to enhance security, trust, and accountability in cloud computing environments. This area addresses challenges such as data integrity, unauthorized access, auditability, and single points of failure in traditional cloud architectures. Key research directions include blockchain-based access control and identity management, secure data sharing and storage using smart contracts, and decentralized authentication and authorization frameworks. Other emerging topics involve integrating blockchain with cloud–edge–fog infrastructures, privacy-preserving blockchain protocols, and blockchain-enabled intrusion detection and threat intelligence sharing. Additionally, research on scalability, consensus mechanisms tailored for cloud applications, cross-cloud blockchain interoperability, and blockchain-assisted SLA enforcement represents significant avenues for advancing secure, transparent, and resilient cloud computing systems.