I need to proof that a user of my app is in possession of the correct SIM card.
On android devices, this is possible by simply sending a challenge within an SMS to the corresponding number (the proof that a user belongs to a specific phone number is not discussed here). As an android app can receive SMSes programmatically, the transmitted challenge can then be sent back to the server using the data connection. Obviously, there is more security to be implemented (e.g. digital signature of the challenge), but this is not relevant here.
Reacting programmatically to incoming SMSes is not possible with iOS. Does anyone have an idea how to proof the possession of the correct SIM card in iOS?
Thanks in advance.