Identification of Actors for WhatsApp (Messaging Application)

In the context of WhatsApp, actors are the users or systems that interact with the application to perform specific tasks. These actors can be classified into different categories based on their roles and responsibilities within the system. Here is a breakdown of the primary and secondary actors of WhatsApp.

Primary Actors:

End User (User/Customer):

The main actor in the WhatsApp system. The end user is the individual who uses the app to send and receive messages, make voice/video calls, share media, and manage contacts and settings.

Responsibilities:

• Sending and receiving messages (text, voice, images, videos, documents, etc.).
• Making voice and video calls.
• Updating their profile information (e.g., profile picture, status).
• Managing contacts and group settings.
• Viewing and updating their status updates.

Admin (Group Administrator):

A special type of user responsible for managing group settings, adding/removing participants, and moderating group activities.

Responsibilities:

• Creating and managing groups.
• Adding and removing members from the group.
• Changing group settings (group name, group icon, etc.).
• Assigning other users as group admins.
• Managing permissions within the group.

Secondary Actors:

Server (Backend System):

The backend infrastructure that supports the application by handling tasks such as message delivery, media storage, data synchronization, and user authentication.

Responsibilities:

• Handling user registration and authentication.
• Storing and synchronizing messages, media, and contacts.
• Managing server-side processes for push notifications.
• Ensuring message encryption and secure transmission between devices.
• Storing and retrieving user data from cloud storage for backup and restore.

Push Notification Service:

The system responsible for sending notifications to users about new messages, incoming calls, and other activities even when the app is not actively in use.

Responsibilities:

• Sending real-time push notifications for new messages, calls, and group updates.
• Ensuring the delivery of notifications on different devices and platforms (iOS, Android).

Third-Party Authentication Service:

A system that handles user authentication using external services such as Google, Facebook, or other identity providers.

Responsibilities:

• Facilitating secure and alternative login methods for users.
• Verifying the user’s identity in conjunction with the WhatsApp registration process.

Media Storage Service (Cloud Storage):

The cloud service responsible for storing and managing shared media files (e.g., photos, videos, documents) that users send through WhatsApp.

Responsibilities:

• Uploading and downloading media files securely.
• Compressing media files for faster transmission.
• Providing cloud backup and recovery options for media files.

Encryption/Decryption System:

A critical system component responsible for ensuring that messages and media shared through WhatsApp are encrypted end-to-end, so that only the sender and recipient can read them.

Responsibilities:

• Encrypting messages and media before sending them to the server.
• Decrypting messages on the recipient’s device.
• Maintaining secure key management and preventing unauthorized access.

External Actors:

Internet Service Provider (ISP):

The external entity that provides internet connectivity for the users and facilitates data transmission between WhatsApp servers and user devices.

Responsibilities:

• Ensuring a stable internet connection for message delivery.
• Providing network infrastructure for seamless communication.

Device Manufacturer:

The hardware provider (e.g., Apple, Samsung, etc.) that produces the devices (smartphones, tablets) on which WhatsApp is installed.

Responsibilities:

• Providing the operating system (e.g., iOS, Android) required for WhatsApp to function.
• Ensuring compatibility between the app and the device’s hardware capabilities (camera, microphone, etc.).