The Probability of Trojan Attacks on Multi-level Security Strategy Based Network

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 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. Finally the model is applied to a military network information system, and the results are reasonable.