The rapid growth of cloud-based web applications has increased the demand for secure data storage and controlled data sharing mechanisms. Traditional cloud storage systems often expose sensitive information to unauthorized access, making data confidentiality a critical concern. This project presents a Hybrid End-to-End Encryption Architecture for a Secure Web Application System, developed using the Django framework to provide secure file storage and sharing in a cloud environment. The proposed system consists of three entities: Administrator, User, and Cloud Service Provider (CSP). The administrator manages user authentication and approval, while users can upload, share, and access files through a secure cloud platform. Before storage, uploaded files are encrypted using the AES-GCM (Advanced Encryption Standard - Galois/Counter Mode) algorithm, ensuring data confidentiality and integrity. A request-based access control mechanism is implemented, where users must obtain authorization from the CSP before accessing files owned by other users. Upon approval, a unique secret key is generated and provided to the requester, enabling secure access to the requested resource. The system also supports user profile management, file ownership verification, access request handling, and controlled file downloading. By integrating strong encryption techniques with cloud-based access control, the proposed architecture effectively protects sensitive information from unauthorized access while maintaining system usability and efficiency. Experimental implementation demonstrates that the system provides a secure and practical solution for confidential file storage, sharing, and management in modern web application environments.

Keywords: Secure Cloud Storage, End-to-End Encryption, AES-GCM, Django Framework, Cloud Service Provider, Access Control, Secure File Sharing, Data Confidentiality.