Based On A Directed Graph Of Network Security Risk Assessment Study

With the rapid development of computer networks, in particular the popularity of Internet in China in recent years, there are increasing attacks on network systems. So network security is put in a serious test. It is certain that network risks exist because of the widespread vulnerability of the net and of possible threats and attacks. Therefore it is quite necessary to make assessment on the security of a network. network Security Risk Assessment is one of the key technologies in active security defense of a network and it is of great importance to guarantee a network's safety. It is also one of the popular study subjects.The paper analyzes the main factors threatening present network security and studies the development and present situation of assessment standards from home and abroad. Based on the analysis regular ways to assess the security of a network are summarized. By comparison the proper assessment ways are sorted out. Then the writer presents an assessment on a directed graph network security. The factors involved in the assessment, such as assets, assets value, threats and vulnerability, are clarified and quantification principles of these factors are also given. By combination of both qualitative analysis and quantification analysis, the assessment on the value of the master computer and on the possibility of bugs and utilizing bugs is made. So the quantification value of the security risk of a target master computer is got and the risk level is set. The paper also gives specific calculations in this respect.The risk assessment on a directed graph network security is to analyze dangerous paths and key intersections in a network by making use of knowledge about digraphs and topology and of path analysis and of corresponding calculations. So network security measures could be taken accordingly and making-ups for the vulnerability could be done in order to improve network security as a whole.