关键词: 网络隐蔽通道模型, BLP模型, 机密性, 共享文件, 协议性能

Abstract: Network covert channel technique is a secret information leaking channel which violates the Bell-La Padula (BLP) model by avoiding the detection of mandatory access control measures, which threatens the confidentiality of high level information. The authors first discussed the relations between covert channel and non-discretionary access control model, and then formed the covert channel model by designing different protocols of covert channel model according to different number of shared files under the assumed scenario and transmitting pattern. The performances of this kind of network covert channel model led by these protocols were compared by experiments, and the extent of threat to the confidentiality they might make was discussed separately. Finally, the authors summarized the transferring characteristics of the model generated by these protocols and the menace they might bring, which made sense to the prevention of the network covert channels.

Key words: network covert channel model, Bell-La Padula (BLP) model, confidentiality, shared file, protocol performance