Network security threats situation assessment and analysis technology study

High level services would suffer threat of varying degrees indirectly from attacks for bottom layer. Most evaluation method applied in current time has not taken the indirect attack into consideration as well as for that of indirect threat and multi-source attack. This paper has proposed a new evaluation method applied upon the crisis and problems based on dependency relationship between bottom layer service and high level services. The dependency relationship is obtained from the management information of the system and monitoring record of network communication, which is applied as the criterion in distinguishing attack directly and indirectly, which is transported over the dependency. On the other hand, the method would fit multi-source attack with non-linear method for evaluation. A general evaluation for the service system would be given based on threat level obtained above. The actual application experiments have proved the feasibilities and practical applicability of the proposed method in the paper.