Research On Safety Authentication Mechanism Of Train-ground Based On LTE-R

As a transmission carrier for communication signals between trains and the ground,the railway wireless communication system is a key component of the train operation control system,also an important infrastructure for ensuring the safety of train operation.Furthermore,it's the core equipment for building intelligent and informationized railway system in the future.GSM-R is the most widely used railway wireless communication system in the global railway industry.It has been in operation for more than 30 years.Unfortunately,subject to the characteristics of narrowband communication technology,GSM-R is difficult to meet the requirements of high-speed railway systems for reliable transmission of high-redundancy data,real-time multimedia video surveillance and other services in the future.Therefore,the International Union of Railways(UIC)proposes to develop a next-generation high-speed railway wireless communication system based on LTE-R.Compared with GSM-R,LTE-R is based on Long Term Evolution(LTE),which has the advantages of high bandwidth,low latency and high data transmission speed.Meanwhile,some other characteristics such as more open air interface,all IP and flat network architecture make it's vulnerable to data eavesdropping,tampering,spoofing,DoS attacks and other security risks.The attacker can take advantage of the weaknesses of the protocol to access the LTE-R network illegally,and tamper with confidential data such as train control and scheduling information to compromise traffic safety.Hence,how to authenticate the identity of the access equipments,and protect the confidentiality and integrity of the data,to meet the access security requirements of the LTE-R system and the real-time requirements of the vehicle domain certification has become a research hotspot.In addition,in view of the advantages of LTE broadband communication technology,LTE-R not only meets the basic communication for trains operation,but also has the ability to provide mobile communication and network services to passengers.However,mobile communication in high-speed railway environment faces authentication signaling congestion caused by large-scale user instantaneous access networks and frequent communication handover.Which seriously affect the user's communication experience.Consequently,research on group access and handover authentication algorithms for LTE-R has become another hot spot.In this paper,we focus on the need for the safe and efficient train-ground authentication mechanism based on LTE-R,which mainly includes the following contents:(1)Firstly,we review the knowledge of number theory and cryptography related to our research,including group,field,elliptic curve and bilinear pairing and related mathematical difficulties in the basis of number theory,message authentication code and digital signature in cryptography.In addition,a series of methods for cryptographic protocol security analysis are introduced,including provable security theory and ProVerif,an automated protocol analysis tool.Besides,the LTE network architecture and the EPS-AKA protocol are briefly introduced.(2)Secondly,aiming at the potential security risks of wireless access procedures in LTE-R networks,a secure train-ground authentication key agreement scheme based on hybrid cryptosystem is proposed.It can ensure the security of LTE-R network access and meet the real-time and high-efficiency requirements of train-ground signaling interaction.The proposed scheme includes three protocols: initial authentication,re-authentication and handover authentication,and can implement IMSI confidentiality protection and effectively prevent DoS attacks,replay attacks,redirection attacks and man-in-the-middle attacks.Then,we use ProVerif to verify the security of the proposed protocol and compare it with other similar protocols.The results show that the proposed scheme can meet the expected security goals and has advantages in computing and communication efficiency.(3)Finally,focusing on the problems of authentication signaling congestion caused by a large number of passengers access network instantaneously and frequent handover in high-speed railway mobile communication environment,the relay server(MRN)is introduced into LTE-R network.Based on this new network structure,a certificateless aggregate signature authentication scheme for passenger groups is proposed.Benefit from the introduction of MRN and the high efficiency of certificateless aggregate signature batch verification,the proposed scheme can realize a large number of users fast access authentication and efficient handover authentication.In addition,we prove the unforgeability of the proposed signature scheme under the random oracle model(ROM).Furthermore,we use ProVerif to analyze the security of the scheme.The results show that the proposed scheme has excellent performance in mutual authentication,key security and resistance to various attacks.Compared with the current 3GPP standard authentication protocol and other similar solutions,the proposed scheme has advantages in terms of computational efficiency and signaling overhead.