<p>The advent of cloud computing has revolutionized data management, providing scalability and cost-effectiveness. However, it also presents challenges in ensuring data security and privacy. Thus organizations increasingly adopt multi-cloud storage strategies to avoid data loss and single points of failure, but a new array of complexities emerges, particularly related to secure data access and management with a multi-cloud strategy. This paper explores these complexities and presents an innovative encryption-based solution for secure data storage and easy accessibility in a multi-cloud system. In this work, we proposed CloudLock framework which uses hybrid ChaCha20-Poly1305 encryption mechanism to store and access the data in multi-cloud systems. Moreover, the secret key used for encryption and decryption is shared between the data owner and authentic users using Elliptic Curve Diffie-Hellman (ECDH) mechanism. Our focus is to establish a robust mechanism that permits only authenticated users to access and manage their data across multi-cloud platforms. Thus with the proposed model, we aim to balance security, accessibility, and efficiency, thereby offering a potential solution to multi-cloud storage’s multifaceted challenges. Our rigorous security assessment and performance analysis, which considers a broad range of parameters including encryption and decryption time, upload and download time, turn-around time, and memory usage, affirms that our proposed framework is highly efficient. The framework meets the stringent requirements necessary for secure data sharing, demonstrating robust resilience to various security threats. When compared to existing methods, our proposed framework showcases superior performance and enhanced security characteristics.</p>