Messaging app WhatsApp is inviting its users to a limited public beta test of its new cross-device syncing feature, which will allow people to use the service on devices that aren't smartphones, without the registered phone having to be turned on.
Using WhatsApp on Multiple Phones | Two Phones at Once!
The beta test was announced on parent company Facebook’s official engineering blog and will only be available to a small group of users in the WhatsApp beta program. As time goes on, WhatsApp plans to expand its beta test and give more people a chance to check out the new feature, albeit slowly.
Currently, WhatsApp allows users to use the service on other non-phone devices such as tablets or desktops, but they must maintain a direct and secure link to the phone app. If the phone runs out of battery or something happens to the app, for example, it crashes and WhatsApp cannot be used. Besides the fact that the app can actually be used, there is also the issue of security, privacy, and consistent message history across devices.
According to that blog post, the biggest challenge was ensuring that the user experience was secure across all devices. WhatsApp solves this problem by giving each non-phone device its own identity key. WhatsApp currently gives users a single identity key for their phone to handle encrypted messages. And to verify that the device a user is messaging from is legitimate, WhatsApp uses security codes to represent all of a person’s connected devices, allowing anyone calling to verify the devices.
