Vol. 7, Issue 1, Part B (2025)

With the surge in cloud computing adoption, cloud storage services have become a cornerstone of modern digital infrastructure. Despite their many benefits, these platforms continue to face significant security challenges, including unauthorized data access, poor management practices, and targeted cyber threats. A major concern arises from the loss of direct control over data once it is offloaded to cloud environments, thereby increasing its vulnerability to compromise. To tackle these issues, this project introduces a novel security architecture that synergizes blockchain technology with cloud computing to enhance data protection. The proposed framework leverages homomorphic encryption to preserve data confidentiality and uses a blockchain-based verification mechanism to maintain data integrity. At the core of this model is a trustworthy Cloud Service Provider (CSP) platform that utilizes a cryptographic approach to safeguard stored information. In this design, the CSP routinely generates a comprehensive hash value representing the state of its entire database, storing this value on a private blockchain. Clients are empowered to validate data integrity by comparing current hash values with those on the blockchain, allowing any unauthorized changes to be quickly identified. This decentralized validation mechanism ensures data cannot be altered undetected, reinforcing trust between users and the service provider. Additionally, data exchange within the system is governed by smart contracts, which require all participants to commit their intentions beforehand through escrow mechanisms, promoting honest behavior. The protocols established in this model ensure critical security features such as data confidentiality, integrity, anonymity, non-repudiation, and privacy. This creates a secure and trustworthy environment for managing, storing, and sharing information in the cloud.