WhatsApp first officially confirmed the existence of multi-device support during an interview where both company chief Will Cathcart and Mark Zuckerberg were present. The early June confirmation provided WhatsApp fans a timeline for the launch of some new features, including support for multiple devices.
Now, the company has officially started rolling out the feature to beta testers. Will Cathcart made the announcement through his official Twitter handle. In his tweet he said, ” Very excited to be launching a beta of our new multi-device capability for WhatsApp. Now you can use our desktop or web experiences even when your phone isn’t active and connected to the internet. All secured with end-to-end encryption.”
The company has also confirmed that despite support for multiple devices, will be maintained. During the interview with WAbetaInfo in June, both Zuckerberg and Cathcart claimed that one of the biggest challenges to support multiple devices was to maintain end-to-end encryption.
WhatsApp chief Will Cathcart, in a blog claimed that in order to achieve the end-to-end encryption the team had to rethink WhatsApp’s architecture and design new systems to enable a standalone multi-device experience while preserving privacy and end-to-end encryption.
In its official blog, WhatsApp explains that prior to the introduction of multi-device, everyone on WhatsApp was identified by a single identity key from which all encrypted communication keys were derived. With multi-device, each device now has its own identity key.
The WhatsApp server maintains a mapping between each person’s account and all their device identities. When someone wants to send a message, they get their device list keys from the server.
For the end-user all that matters is that they will be able to access WhatsApp without the need to stay connected on the primary phone and even with this new feature, the messaging application has confirmed end-to-end encryption.