一种基于扩频编码的可靠网络隐蔽信道设计方法

针对网络隐蔽信道在强噪声环境中信息传递错误率高的问题，该文提出一种基于CDMA扩频编码的可靠网络隐蔽信道设计方法。该方法利用数据包在传输过程中的包际时延传递隐蔽信息，发送方采用散列扩频编码，接收方采用信道噪声预测消除等技术进行信道抗干扰处理，提高了强噪声环境中隐蔽信道通信的可靠性。针对信道抗干扰性与信道传输率两个主要衡量指标互斥、综合性能难以达到最优的问题，提出了基于选定传输率的抗干扰能力最优化方法。在TCP/IP网络中构建了该隐蔽信道，并进行了隐蔽信息传输实验，结果表明该文方法与解决同类问题的其他方法相比隐蔽信道数据传输的综合抗干扰能力提高20%左右。

A Robust Network Covert Channel Algorithm Based on Spread Coding

In order to solve the problem that the covert timing channel works unstable in the noisy network, a method of designing robust covert channel is proposed. The method uses the interval time of network packets to transfer information, the sender codes covert information using hash spreading spectrum, and the receiver forecasts the channel noise and eliminates it. In order to solve the contradictory relationship between transmission rate and robustness, the strategy of maximizing robustness under fixed transmission rate is proposed. The experimental environment of this covert channel is constructed and several experiments are conducted. The results show that the ability to resist noise is increased about by 20%, compared with other methods on the same problem.