Verification Schemes of Multi-SIM Devices in Mobile Communication Systems
Takahito Yoshizawa, Bart Preneel · 2020
Multi-SIM capable mobile phones have been gaining popularity. Due to the absence of standardized solution, there are implementation variations in the User Equipment (UE) from both hardware and software perspectives. Especially, coordination of call events on multiple SIMs requires standardization as it involves interaction between the Core Network (CN) and the UE to avoid negative user experience such as missed incoming call or interrupted data session. 3rd Generation Partnership Project (3GPP) has an ongoing work to addresses this area in Release 17. However, security aspects are outside the scope, including mechanisms to verify multiple SIMs in a device. In this paper, we address this gap by proposing variations of verification schemes using crypgographic operations to help mobile networks to identify the device capability of the UE and verify multiple SIMs in it. The proposed mechanisms are simple and effective to meet the goal. Based on our investigation, we believe this is the first proposal to address this aspect in the multi-SIM devices in the mobile system.