The beta test was announced on parent company Facebook’s official engineering blog and it will only be available to a small group of users on the WhatsApp beta program. As time moves on, WhatsApp plans on expanding its beta test and allowing more people to come in to check out the new feature, albeit slowly. Currently, WhatsApp allows users to use the service on other non-phone devices like tablets or desktops, but they must keep a direct and secure link to the phone app. If the phone’s battery dies or something happens to the app, for example, it crashes, and WhatsApp can’t be used. In addition to actually being able to use the app, there’s also the matter of security, privacy, and message history consistent throughout the different devices. According to that blog post, the biggest challenge was making sure the user experience was secure across all the devices. WhatsApp is solving this issue by giving each non-phone device its own identity key. WhatsApp currently gives users one identity key for their phone to handle encrypted messages. And to verify that the device a user is sending a message to is legitimate, WhatsApp is using security codes to represent all of a person’s connected devices, allowing anyone on a call can verify the devices. Users also will be able to see when all of the non-phone devices linked to the account were last used, and log out of them remotely. Message and data history (this includes contact names and archived chats) will be synchronized throughout the devices and end-to-end encrypted so nothing is lost. Even metadata is kept. If a WhatsApp user wants to sign up for the beta, WhatsApp has a help page that details the steps on how to join or leave the beta.
