Research And Implementation Of Combined Covert Channel Based On Pseudo - Random Sequence

With the rapid development of the Internet industry, the relationship between people’s daily lives and the Internet has reached the point inseparable. The rapid growth of the Internet has brought great convenience to people’s daily lives. At the same time, it also brings a lot of problems about security issues. Unlike other transfer encrypted ways, covert timing channel use each packet’s interval characteristics of normal channel to represent certain secret information, rather than directly send secret information. So it is more difficult to be detected by communication system.Covert channel transmit secret information by the normal channel. It has many kinds of structure. Most of current network covert timing channels are based on the specific rules of inter packet intervals. Once intercepted, the secret information will probably be deciphered and there will be a serious threat to the security of secret information.This paper presents a method of covert channel’s building with pseudo random characteristics. The new covert channel can jump on a variety of types according to the pseudo random code. Firstly, this paper summarizes the advantages and disadvantages of each kind of covert channel. Combined with the existing channels are unable to ensure privacy data security, the constructing method of new covert channel based on pseudo random code is proposed. This paper introduces the principles and algorithms of constructing pseudorandom code, construction of each channel and synchronous mode of covert channel transmitter. We can divide covert information into a plurality of data blocks and distribute to a plurality of covert channels.By this way, even if there is a-part of covert channel detection party interception, they cannot access to the integrity of the original secret information. This paper builds a clear statement of how to implement a covert timing channel of high data security. In order to further improve the anti-detectable of the covert channel. And it also adopts the method of sparse embedded, which effectively improve channel entropy. At the same time, the transmission rate and the correct rate of covert channel achieved very good balance point.