How are messages sent on WhatsApp - briefly?
Messages on WhatsApp are sent through a process called end-to-end encryption, which ensures that only the sender and recipient can read them. The data is transmitted over the internet using standard network protocols.
How are messages sent on WhatsApp - in detail?
Messages on WhatsApp are sent through a complex process involving multiple layers of security and encryption to ensure privacy and data integrity. The process begins when a user composes a message and taps the send button. Here’s a detailed look at how messages are transmitted:
- Message Composition: When a user types a message, it is first processed by the WhatsApp application on their device. This includes formatting text, adding emojis, or attaching files such as images or videos.
- Local Encryption: Before being sent over the network, the message is encrypted locally on the user's device using end-to-end encryption. WhatsApp uses the Signal Protocol, developed by Open Whisper Systems, for this purpose. This ensures that only the intended recipients can read the message.
- Message Header: Each message includes a header with metadata such as the sender’s phone number, the recipient’s phone number, and a unique identifier for the message. This header is also encrypted to maintain privacy.
- Network Transmission: Once encrypted, the message is sent over the internet to WhatsApp's servers. The transmission path typically involves the user’s local network (Wi-Fi or mobile data), followed by routing through various internet service providers (ISPs) and potentially a content delivery network (CDN).
- Server Relay: WhatsApp servers act as intermediaries, relaying the encrypted message to the recipient's device without decrypting it. The servers do not have access to the message contents due to the end-to-end encryption. This ensures that even WhatsApp itself cannot read the messages.
- Delivery to Recipient: When the encrypted message reaches the recipient’s device, the WhatsApp application decrypts it using the recipient's private key. The process of decryption is seamless and instantaneous, allowing the recipient to read the message as soon as it arrives.
- Read Receipts and Status Updates: After delivering the message, WhatsApp can also send a read receipt back to the sender if the recipient has enabled this feature. Similarly, status updates or delivery notifications are sent from the server to both parties involved in the conversation.
This entire process is designed to be fast and efficient while maintaining a high level of security and privacy for users. WhatsApp's end-to-end encryption ensures that only the intended recipients can access the message content, providing a secure communication channel for over 2 billion users worldwide.