Thanks! You mention that this is the simplest version, is there one where you use distinct keys? Also, regarding the IMEI - let‘s assume the UE nullified it, h

Thanks! You mention that this is the simplest version, is there one where you use distinct keys? Also, regarding the IMEI - let‘s assume the UE nullified it, how would you distinguish between a legitimately nullified UE and a stolen UE that had its IMEI nullified?