Research on Blockchain Technology for Cloud Security focuses on leveraging the decentralized, immutable, and transparent properties of blockchain to enhance data integrity, confidentiality, and availability in cloud environments. Blockchain-based frameworks enable secure access control, tamper-proof data storage, and verifiable audit trails, mitigating risks such as unauthorized access, data breaches, and insider threats. Integration of smart contracts and consensus mechanisms facilitates automated security enforcement and trust management across multi-tenant and hybrid cloud infrastructures. Recent approaches explore combining blockchain with cloud services for secure data sharing, distributed storage, and enhanced authentication, providing a resilient and transparent security layer that strengthens overall cloud computing trustworthiness.