Research On Construction And Detection Method Of Covert Channel Based On LTE-A System Communication Protocol

With the rapid development of informationization in human society,the problem of information security are becoming more and more prominent.The protection of private information,such as national security,trade secrets and personal privacy,has attracted more and more attention.Usually,in order to ensure the safety of the important data in communication,cryptography-based methods are used to encrypt data before its transmission.However,in some cases,encryption methods can't effectively conceal the behavior of the communication.One branch of information security,information hiding technology has attracted researcher's attention.Covert channel is an extension of information hiding technology based the network.So far,researches have proposed a lot of methods for constructing different kinds of covert channels.Especially,as the rapid development of LTE-A technology,the con?ditions for constructing a covert channel are becoming more convenient.And because the openness and the mobility of the LTE-A network system,it is difficult for detection of covert channel in it.More and more private information are leaking from your smart terminal via the hidden channels without knowing.It is helpful for us to understand and utilize the hidden channel of the mobile network,and to ensure the security of the LTE-A mobile communication network,and to ensure the future of our country to win the information war.It is of great significance to study the construction and detection methods of the covert channel of the LTE-A system communication protocol.Studying the construction and the detection methods of covert channel in LTE-A system commu-nication protocol,can bring us to recognize and utilize the hidden channels of the mobile network and guarantee the security of the LTE-A communication network.And it has a great significance in ensuring our country can win the future warfare of information.In this dissertation,we study the construction and the detection methods of covert channel in LTE-A.The main research contents are as follows:In terms of the construction,we have designed two hidden information synchro-nization methods for storage LTE-A covert channel,based on network event-triggered hybrid LTE-A covert channel and pre-shared synchronization mechanisms LTE-A covert channel.We have explained the construction principles and theoretical analysis of the two kinds of covert channel respectively,and relevant experiments are carried out based on the NS3 simulation platform.Experimental results show that both of them have good performance in transmission capacity for hidden information.In terms of the detection,we have analysed the characteristics of PDCP and RLC layer's sequence number field in normal network and covert network data flow,and proposed two kinds of PDU level based semi-blind detection classification method:confidence distribution zone of the difference value and corrected conditional entropy.And based on the fingerprint characteristics of the data flow,we have trained and tested our two detection classification by the data set from the simulation network.Both of them have achieved a good performance in detection of covert storage channel over LTE-A.