:D, so you need to write down that key or remember it when you want to use on another device or if that key is provided somehow,such as pushing a request to pr

:D, so you need to write down that key or remember it when you want to use on another device or if that key is provided somehow,such as pushing a request to provider to get it using internet, then what happened when there is no connection but gsm or imagine when you use that key for few devices? what will be your main device and you want to suspend the others? Many problems must be solved if you'd like to use a key instead of a SIM card :D