Research And Implementation Of Authentication Function In TETRA Digital Trunking System

Terrestrial Trunked Radio(TETRA)digital trunking system is a professional dispatching communication system,which is mainly used in government,public safety,electric power,transportation,logistics,petrochemical and military departments.Authentication function refers to verifying whether a user has the right to access the system.It uses an identity recognition mechanism to allow authorized users to access the network to enjoy resources,and to a certain extent,protect the security of TETRA digital trunking system.Due to the European embargo on the authentication function of the TETRA digital trunking system,on the other hand,if there is no authentication function,the domestic TETRA digital trunking system may be attacked by a pseudo base station or a pseudo terminal,causing the network breakdown.As a result,localization of the authentication function of the TETRA digital trunking system must be realized.Therefore,the research on the authentication function of TETRA digital trunking system has important practical value.This article describes the architecture and authentication functions of TETRA digital trunking system,analyzes the structure and function of Mobile Link Entity(MLE),the structure and function of the Mobility Management(MM)entity,the function of the database and the function of the authentication center based on the review of research status of the authentication function of mobile communication systems at home and abroad.The main works are as follows:1.A communication mechanism among authentication related modules and an authentication signaling process of air interface are proposed based on the relationship among MLE,the MM entity,the database,and the authentication center.The interface between the MM entity and the MLE,the interface between the MM entity and the database and the interface between the MM entity and the authentication center are designed;2.According to the classification of cryptosystems,block ciphers and sequence ciphers,the Advanced Encryption Standard(AES)and the SMS4 algorithm are analyzed and compared,and the security and encryption time of AES and the SMS4 algorithm are analyzed based on the authentication mechanism of a user by the TETRA digital trunking system infrastructure and the authentication signaling process of air interface,and the SMS4 algorithm is selected as the authentication algorithm of TETRA digital trunking system;3.An MLE module,an MM module,an authentication parameter request timer module,and an authentication result request timer module are developed based on the Windows operating system,in the Tau G2 development environment,using the C language.And based on the authentication-related tables in the Home Location Register(HLR),the program that calls the SQLite database is developed and the authentication function of TETRA digital trunking system is implemented;4.Test cases of the TETRA digital trunking system authentication function are designed.Function test and protocol conformance testing are performed on the authentication function.The results of the test show that the authentication function of the implemented TETRA digital trunking system meets the design requirements and is applied to the Beijing Subway 8 Extension line.