WhatsApp promises to sync between multiple devices without relying on a mobile phone

Although WhatsApp users can use messaging across multiple platforms, smartphone connectivity is still required, due in large part to the way WhatsApp handles the end-to-end encryption (E2EE) issue.

This is about to change, and eventually the user will not need to have a mobile phone nearby to use WhatsApp on the web, macOS, Windows or Portal.

From now on, WhatsApp will ask users to try the beta phase on multiple devices. It is possible to use the Service on your mobile phone and up to four other devices (as long as they are not mobile phones either). WhatsApp will be testing cross-device communication with a small group of people from its beta program. They will be able to disable the trial version later. With the help of these users, WhatsApp will simplify the experience across multiple devices and add a few more features before rolling it out more widely.

Although many users requested support for multiple devices, WhatsApp took some time for that to happen. It created a system that maintains end-to-end encryption while allowing people to sync data like contact names, files, and starred messages between devices.

Until now, WhatsApp for smartphones has been a primary channel of the service. Other platforms, such as web and desktop applications, maintain a firm and secure link to the mobile application and mirror the content. But if your phone battery is dead or there is a problem with the smartphone app, it becomes impossible to use WhatsApp on other platforms.

By testing on multiple devices, each device will have its own identity key. Currently, users have a unique identity key (i.e. the key on their mobile phone) to handle encrypted messages. WhatsApp has developed systems that will prevent snoopers from trying to add devices to a user’s account and reduce the number of times people need to confirm their identity on devices. The user will also be able to control the connected devices and will see the devices associated with their account.

Besides messaging, WhatsApp will get E2EE support for audio and video calls as part of the test across multiple devices. There will be no impact on how WhatsApp handles cloud backups.

Solving an issue with E2EE support on user devices can be difficult because only the devices to and from which messages are sent should be able to decrypt them. It seems Apple has found an answer – iMessage supports E2EE on all Apple devices. Although Telegram works across multiple devices, the E2EE (Secret Chats) method does not currently. As with the current WhatsApp setup, the Signal desktop app also needs to be connected to a smartphone to send and receive messages.

Source: Engadget