WhatsApp is conducting limited public testing to ensure that the platform’s functionality is available for multiple devices. According to WhatsApp, you’ll be able to access your messages on these different devices even if your phone’s battery runs out. This dispenses with the current arrangement whereby the first system remains connected and continues to be used on another device.
Currently, WhatsApp connected to at least one account number can only be used on cell phones. Customers will still be able to access their computers via WhatsApp Internet, but this will depend on the ability to maintain the phone connection. With the launch of the new public beta, this could change.
Learn more about how to use WhatsApp features on multiple devices
You may not be able to take advantage of this feature, as the functionality to use the secure version of WhatsApp has not yet been rolled out. According to the company’s weblog, it plans to “explore our experience with a small group of customers who are participating in our current beta program.” It will also be “rolled out slowly after optimizing efficiency and adding some additional options.” It’s not yet clear if this feature will be available to all Android and iOS beta users.
So, what does WhatsApp support on multiple devices look like?
The first, on the other hand, is “the only system that lets you encrypt messages and initiate calls for others end-to-end.” Related devices, such as desktops and laptops, mirror WhatsApp content on the phone and use their own personal interface (UI).
But what about end-to-end encryption and privacy?
WhatsApp uses a client-side output method, which means that “messages sent by WhatsApp users are encrypted and sent in N different ways to N completely different devices: the sender’s and recipient’s system lists.” Messages are “individually encrypted using a paired encryption session set up on each system.”
In addition, messages are generally not stored on servers after delivery, and WhatsApp continues to use the same scalable sender key encryption scheme as the Sign protocol. In addition, all phone and video calls, including group calls, are end-to-end encrypted.
WhatsApp says it has tried to solve the problem of servers eavesdropping on people’s conversations by adding a number of features to their accounts. First, they expanded security codes that “can now describe any combination of a person’s system ID.” These codes are used to determine which device a contact sends a message to.
As a second step, a technology called automatic machine authentication could be introduced later. The report explains that “this technology mechanically establishes a trust relationship between units and matches it with another person’s security code if they re-register their entire account, rather than having to associate an entirely new system with their account each time.”
Customers will also have the ability to manage and protect the devices linked to their account. First, all individuals will need to hyperlink to the new companion device by scanning a QR code on their cell phone. This process will require biometric authentication prior to linking, if the person has enabled this feature on the relevant device.
Finally, the person will be able to see all partner devices linked to their account, as well as the date and time of their last use, and can even log out remotely if necessary.
This new feature “synchronizes message history and various utility status information (e.g., contact name, whether a chat is archived, whether a message is marked with an asterisk, etc.) across all devices. This knowledge is then encrypted from generation to generation between devices.
The paper further explains that when the companion systems are connected, “the first system encrypts the information about the current chat and passes it on to the newly connected system. Important content in this area is transferred to the completely new system.” Once the companion system has downloaded the message, decrypted it, unwrapped it and stored it securely, the key is removed. The companion system then retrieves the information history from its own database,” the blog states.
For individual pieces of actionable information, such as the number of contacts or the time a message was sent, “WhatsApp’s servers securely store a copy of each piece of actionable information accessible from each person’s device,” WhatsApp says. This information is “encrypted end-to-end using a constantly changing key that can only be learned on each person’s device.”