| In recent years,telecommunications fraud has become increasingly fierce.Pseudo Base Stations are currently used as the main tools of fraud activities.Pseudo Base Stations forcibly send spam message,fraud message,phishing site to obtain benefits.One of the traditional identification methods for spam message is to mark the spam messages by intercept software.The intercept software integrates the phone number that marked by users and stores it in the share-databases.When users are attacked again by the same phone number,it reminds the users or intercepts the spam messages;the second method is based on single signal strength.When Pseudo Base Stations sends spam message,it needs to increase Radio Frequency signal strength,if the signal strength exceeds a threshold,then it will alert the users.However,Pseudo Base Station can forge any phone number to attacks user's mobile terminals,the two methods mentioned above have many problems such as low interception accuracy and lack of storage space,etc.This paper mainly analyzes the difference of working principle between normal Base Station and Pseudo Base Station,and proposes two algorithms for detecting and identifying pseudo base station spam message.The new algorithms improve the efficiency of traditional recognition algorithm.On the one hand,the accuracy of recognition is improved,on the other hand,it is easy to implement.(1)The recognition algorithm based on signal perception:The algorithm combines the parameters of signal strength and the effective distance from terminal to base station.The experiments found that when the mobile phone accesses a normal base station,the ratio of the received signal strength and the effective distance will fall within a certain range.With this experimental result,it sets a threshold in the recognition software when implement the Algorithm.When the ratio is lower than the threshold,it alerts the user.The algorithm combines two parameters of signal strength and effective distance,it effectively improves the recognition accuracy compared with the mark methods and single signal strength.(2)The recognition algorithm based on Digital signature:According to the loophole that Pseudo Base Station sends messages that will not pass through the short message service center,the recognition algorithm based on Digital signature is proposed.The algorithm adds the signature part to the short message service center and verification part at the mobile terminal.The accuracy of the algorithm is theoretically achieved 100%.In the recognition mechanism based on digital signatures,because the advantages of elliptic curve cryptosystems,such as high security,short key,and high processing speed,this paper proposes a digital signature algorithm based on elliptic curves,which improves the digital signature verification algorithm,and avoids the inversion process in the operation.The improved digital signature algorithm effectively reduces the running time of the algorithm and makes it more suitable for mobile terminals with weak computing power. |
