Well, the phone number is the identifier. What would happen is that you get a new phone, idenftify via phone number. It would generate new keys but your contact

Well, the phone number is the identifier. What would happen is that you get a new phone, idenftify via phone number. It would generate new keys but your contacts are still around. You contacts all the notifications (if they have turned them on) that you have new keys. I am not sure about chat history, you think its moved to the cloud if you have that activated. Im not 100% on any of this, but I think that is how it works. If you want something that is not bound to your phone, Threema is pretty nice. If you lose your phone and you have no backup, its gone.