Here are the key UML diagrams for the proposed system:
Use Case Diagram:
Actors: User, Cloud Server, Attribute Authority
User can register, upload files to cloud server, download files, revoke access
Cloud Server stores and manages files
Attribute Authority issues/revokes access tokens
Class Diagram:
Key classes:
User - contains user credentials and attributes
File - contains file metadata like name, size, encryption key
AccessToken - provides read/write permissions to a file
Sequence Diagram:
Shows interaction between objects during key processes:
1. File upload - User uploads file to Cloud Server, which encrypts and stores it
2. File download - User requests file