This paper investigates the fraudulent usage of mobile telecommunications services due to cloned subscriber identity modules (SIMs). In GSM or the Universal Mobile Telecommunication System (UMTS), a mobile phone or mobile station uses its SIM to gain network access through authentication. If the SIM of a legal user is cloned, then the cloned SIM can be used for GSM/UMTS authentication and fraudulent usage may occur. Under the existing GSM/UMTS mobility management and call setup procedures, we show how quickly the fraudulent usage can be detected. We also propose a simple solution to speed up the detection of potential fraudulent usage.
['Yi-Bing Lin', 'Ming-Feng Chen', 'Herman Chung-Hwa Rao']
Potential fraudulent usage in mobile telecommunications networks