Data security and access control continue to be significant challenges in Cloud storage, particularly as storage demands and transaction volumes grow, creating opportunities for malicious activities. Ensuring the integrity, traceability, and protection of transaction logs in decentralized Cloud systems is a critical issue. This paper proposes a Blockchain-based approach that leverages Blockchain’s immutability and robust access control methods to tackle these challenges. The system integrates Attribute-Based Encryption (ABE) with multiple authorities, enabling decentralized attribute management and providing fine-grained access control without depending on a central entity. Smart contracts are employed to boost transparency, enforce policies, and reduce computational and communication burdens. The solution ensures that data ownership stays with the original owners, while unauthorized access attempts are quickly detected and recorded for accountability. Evaluation results confirm the system’s efficiency, showing a consistent increase in log entries and faster log retrieval times, even with a buffer size of 104. Overhead tests reveal minimal delays compared to existing methods, and the consistent linear increase in validation times reflects the system’s scalability and performance, ensuring secure and dependable Cloud storage.