Well, it all started when I wanted to take the sim card out of my tablet and I was about to shut it down so that I could take the simcard out. But then a thought raced through my mind, "What if I take out the simcard before I turn off the tablet and go to google and see whether I can still search for something?"
So I quickly took out the simcard and I typed a word in the browser I have never searched for before(I checked my history to confirm) and....... It loaded and displayed a webpage! I clicked on a website very quickly and it also began to load it was almost through but before it fully opened the tablet quickly turned itself off.
This proves a theory I once had:Sim cards are identified on their individual operator networks using the IMSI. Mobile network operators connect mobile phone calls and communicate with their market SIM cards using their IMSIs using a certain format.(Actually that's the factual part not the theory part I was talking about)
(Now the theory part) That IMSI format that is stored in the simcard is accessed by the phone as it transmits that data using a radio link to a cellular network .Now as the device sends this data it stores the same data along with the encryption key of the simcard on its RAM. Since the device here is the middle guy he can store the information being transferred without the simcard or the carrier. Meaning when the device obtains the encryption key it stores it on its RAM as it passes it to the mobile operator requesting access and authentication and once the mobile is granted access to the operator's network it stores the encryption key because the encryption key is used to encrypt all further communications between the device and the network hence having no need for the simcard anymore. Which explains why when I removed my simcard from the device I was able to surf the net. But as a security procedure(one that worked terribly slow allowing me to surf the net for a brief period of time) the tablet turned itself off, and since it was stored in the RAM once it turns off the information is lost. But isn't this a great security concern?
What if someone made a program that overrides the devices settings allowing the stored information to be continually used without having the simcard?
Basically what I'm asking is that, isn't it a great security concern for devices to function this way?