一种基于Web的可靠网络隐蔽时间信道的研究  

Robust Covert Timing Channel Based on Web

作　　者：钱玉文[1] 赵邦信[1] 孔建寿[1] 王执铨[1] 

机构地区：[1]南京理工大学自动化学院,南京210094

出　　处：《计算机研究与发展》2011年第3期423-431,共9页Journal of Computer Research and Development

基　　金：国家自然科学基金项目(60974129;60804035;70931002);江苏省自然科学基金项目(BK2008403;BK2009388)

摘　　要：针对隐蔽时间信道在广域网上无法稳定工作的问题,提出了一种可靠隐蔽时间信道的模型.这种信道利用HTTP协议的网络包的时间间隔作为载体传输隐蔽信息.通过抗干扰处理、接收方确认等方法,设计了可靠的通信协议.采用队列理论对这种可靠隐蔽时间信道进行建模,并推导出了该信道的容量.为了获取该信道的性能指标,在Internet网络中实现了这种可靠隐蔽时间信道,进行了隐蔽信息的数据传输实验.实验结果表明,这种可靠隐蔽时间信道的传输率约为传统隐蔽时间信道的传输率的11倍,在相同的干扰下,可靠隐蔽时间信道的稳定性远好于传统的隐蔽时间信道.In order to solve the problem that the covert timing channel works unstable in the Internet,the model of a robust covert timing channel（RCTC）running on the Web by using HTTP protocol is proposed.In the model,the inter packets delay is used to transmit covert information,and the acknowledge packet of HTTP protocol works as a confirmation of the covert information,which forms a bidirectional covert channel.A reliable communication protocol,which keeps the transmitter and the receiver of the covert information to be synchronization,is designed to ensure the stability of RCTC.To improve the efficiency of covert channel,the encode way of covert information is analyzed,and the scheme of ＂2-bits to one inter packets delay＂ is adopted.The capacity of RCTC is deduced based on queue theory.The experimental environment of RCTC in the Internet is constructed and several experiments of covert communication with the channel are conducted.The results show that the capacity of RCTC is about 11 times of that of traditional timing channel,the robustness of the channel is much better than that of traditional timing covert channel,and the channel can maintain reliable even when the quality of network communication is poor.

关 键 词：信息安全 网络安全 隐写 隐蔽信道 鲁棒性 

分 类 号：TP393.08[自动化与计算机技术—计算机应用技术]