摘要：The network information system based on multi-level security strategy (MLSS) is adopted by many organizations, as it reflects features of mandatory access control. Meanwhile, the network has also attracted a growing number of Trojan horses’ attacks. Considering the relationship between defend ability and security levels, the paper discusses that the Trojan horses’ attacks have a dependency on data path in the network and establishes three attacking probability models of single source node to single target node by single-path, single source node to single target node by multi-path and multi-source nodes to single target node by multi-path. Furthermore the paper describes the defend ability of the non-adjacent nodes with a new model. Finally the model is applied to a military network information system, and the results are reasonable.
关键词：trojan attacks; mlss-based network; probability model; data path; network security
