Just curious about the architecture behind the new whatsapp web, how the new whatsapp web can keep syncronize with new incoming message even when my phone is offline? does whatsapp store user's message in their server now ?
I want to know how the new architecture work, where whatsapp store all the incoming message when primary and linked devices is offline?
According to this article on the FB Engineering blog:
For message history: When a companion device is linked, the primary device encrypts a bundle of the messages from recent chats and transfers them to the newly linked device. The key to this encrypted message history blob is delivered to the newly linked device via an end-to-end encrypted message. After the companion device downloads, decrypts, unpacks, and stores the messages securely, the keys are deleted. From that point forward, the companion device accesses the message history from its own local database.
I'll recommend you go through the full article to understand it better. But to answer your question:
does whatsapp store user's message in their server now ?
- Yes, WhatsApp stores a copy of each application state on their servers, which all devices can access but this data is encrypted and the server does not store messages after they have been delivered.