Develop secure file storage for user documents, ensuring encryption and access control.

## 📌 Description

Develop a secure file storage system for user documents, ensuring encryption, integrity, and controlled access. The system should protect sensitive user data, prevent unauthorized access, and comply with security and data protection standards.

## Acceptance Criteria

- [ ] Implement **AES-256 encryption** for stored documents
- [ ] Store file metadata securely with references in the database
- [ ] Restrict access based on **user roles and permissions**
- [ ] Generate **unique encryption keys per user** for enhanced security
- [ ] Implement **secure access controls** with authentication and authorization
- [ ] Support **file integrity checks** using cryptographic hashing
- [ ] Ensure compliance with **GDPR, CCPA, and other security regulations**

## Tasks

- [ ] Set up **secure storage architecture** (AWS S3, local storage, or other secure solutions)
- [ ] Implement **encryption and decryption** mechanisms for document storage
- [ ] Design a **role-based access control (RBAC) system** for document access
- [ ] Integrate **audit logging** to track file access and modifications
- [ ] Implement **file integrity validation** using SHA-256 or equivalent
- [ ] Conduct **security testing** to ensure robustness against unauthorized access