Cloud computing has become an essential paradigm for modern enterprises by providing scalable, on-demand access to computational resources. Despite its widespread adoption, significant concerns persist regarding data security, integrity, and the trustworthiness of service transactions—particularly due to the centralized nature of conventional cloud infrastructures. This paper presents a novel cloud framework that integrates Ethereum blockchain technology to enhance trust, enforce restricted access control, and secure service interactions. The proposed approach employs a two-factor authentication mechanism combined with blockchain-based smart contracts to authenticate legitimate service requests, record immutable transaction logs, and mitigate prevalent threats such as Distributed Denial-of-Service (DDoS) and Sybil attacks. By embedding access control policies directly into the blockchain, the framework ensures transparency, immutability, and resilience against unauthorized data manipulation. Experimental validation demonstrates the framework's effectiveness in improving the security, reliability, and scalability of cloud environments. The findings highlight the potential of blockchain as a foundational technology for developing trustworthy and robust cloud computing systems.