Research And Application Of Improved Covert Channel Model Based On Packet Sorting

A covert channel is a communication channel.With the popularization of computer networks,people combine covert channels with computer networks.In normal network communication,covert channels can penetrate traditional security firewalls and are difficult to detect.Therefore,it is possible to transmit secret information in military and enterprise fields.This paper analyzes the covert channel of packet ordering and proposes the research and application of the covert channel model based on improved packet ordering.The research contents of this paper are as follows:Firstly,in view of the problem that the covert channel data of the packet ordering is not verified,a data verification model based on the covert channel of the packet ordering(DVCCPO)is proposed.Based on theory,determine the relationship between the ordering of ports and the time interval in the covert channel of packet ordering,and a many-to-one secret communication model is constructed.The research shows that compared with the traditional covert channel of packet ordering,this model can ensure the stable transmission of data and the correctness of the data,and can retransmit the numbers when transmission errors occur,which improves the reliability of the modelSecondly,to solve the problem that the transmission capacity of the covert channel model based on packet ordering is small,a covert channel model based on time interval packet ordering(CCTIPO)is proposed.The function relationship between the number of sending ports of the covert channel,the sending interval of the covert channel and the transmission of the secret information is derived through theory.The transmission efficiency and performance of the model are analyzed.It can be seen that the model optimizes the covert channel of packet ordering and increases the total amount of data transmitted by the covert channel of packet orderingThirdly,in order to solve the problem of poor concealment between the communication parties in the covert channel model based on packet ordering,a distributed covert channel of the packet ordering enhanced model based on data compression(DCCPOEDC)is proposed.The function relationship between the number of nodes,sending interval and transmitting secret information is deduced theoretically.An appropriate data compression algorithm Lempel-Ziv-Markov chain-Algorithm(LZMA)algorithm is selected through experiments and the transmission performance and concealment of the model are analyzed.It can be seen that the model optimizes the covert channel of packet ordering,increases the total amount of data transmitted by the covert channel of packet ordering,and improves the concealment of both communicating parties in the covert channel.Fourth,a keyboard recording system is designed,which can realize keyboard recording and information transmission.The system designed three types of information return modules for data verification,transmission capacity and concealment in three different application scenarios.From the functional requirements of the keyboard recording system,the design of the overall architecture,and the design of the functional modules,the tests of the system are described.In general,in view of the traditional package ordering covert channel analysis,was proposed based on improved package sorting model research and application of covert channel,from data validation,transmission capacity and concealment three aspects to improve the traditional package sorting of covert channel,increased the traditional package sorting of covert channel transmission amount of data,and improve the concealment of the both sides of the covert channel of communication.