Research on the Influence of Network Condition to Network Covert Timing Channels

Interest of covert timing channels is increasing rapidly. A lot of exploitation has been done on the construction of covert timing channels over the internet. But the construction work of covert timing channels is always in laboratory environment. In the real network environment, delay and packet loss influence the transmission quality of covert messages. In this thesis, we introduce evaluation criterion of network condition as a reference of network covert timing channel. Then we do an experiment to verify the influence of network condition to network covert timing channels. When the network condition is busy, there are some letters wrong and lost among covert messages. When network condition is free, the covert messages transmit successfully. From this experiment result, we can see that network condition influences the transmission of covert timing channels deeply. This result has certain significance for the future construction work of network covert timing channel in the real network environment.