When users connect their account on a new device, they will be able to transfer not only messages but also files sent within the last 45 days. However, the developers have provided an option to opt out of this feature if you don't need it and leave messages only on your primary device.
The developers also explained how they managed to ensure user privacy. All Signal account data is stored in a compressed encrypted archive that can be transferred to a new device via the company's servers.
The developers claim that as long as messages are processed on the server, they will be end-to-end encrypted, so even company employees will not be able to access them.
In addition, to link a new PC or iPad to an existing Signal account on an iOS or Android smartphone, the new device must confirm that it has the account holder's permission to connect and receive the keys from the main device. A regular QR code containing all the necessary information will be enough for this.
Next, the developers will work to provide Signal users with the ability to transfer their messages to a new primary device, or to restore messages if the previous primary device is lost.