The Design And Implementation Of Pseudo Base-Station Identification System

With the popularity of mobile terminals and a spurt of development trend of mobile Internet business, pseudo base-station hijacks mobile phone and sends spam message, by using the vulnerabilities of the unidirectional authentication protocol in GSM (Global System for Mobile Communication) network, which poses a threat to the user's personal information and property safety. Although 3G/ 4G network has implemented two-way authentication mechanism, and has been rapid development, a new pseudo base-station can interfere with the signal band and force mobile phone back to 2G, where the upgrade for the USIM(Universal Subscriber Identity Module) card cannot eradicate the problem of pseudo base-station. Exploring real time and effective pseudo base-station identification mechanism has important practical significance.Based on the study of GSM network architecture and protocol vulnerabilities, combining with the pseudo base-station working principle and the features of Android mobile phone, a real-time and efficient pseudo base-station identification scheme is designed. Pseudo base-station induces the mobile terminal location update by setting the extreme LAC (Location Area Code). However, in the GSM network, the LAC values of the normal base station are usually continuous and the numerical difference is not large.There are many cells in the same LAC. According to this characteristic,when the base station occurs handover, the neighboring base station information table is constructed, then the current connection base station and unconnected but signal receivable adjacent base station are recorded.Afterwards, the information is uploaded to the server database for realizing the shared base station to improve a more perfect neighbor base station table. According to the adjacent base station table, pseudo base-station identification system make a preliminary decision, then use the LAC algorithm based on the coefficient of variation to further determine whether the pseudo base-station SMS, improving the accuracy of the pseudo base-station identification. In addition, the system can avoid pseudo base-station error by feedback mechanism. In this paper, the requirement analysis of the pseudo base-station identification system and the detailed design method of the main modules of the client and server are described in detail. Finally,the test results verify the effectiveness of the pseudo base-station identification system.