nvironments and specialized applications It will be very difficult to judgethe correctness of settings.d system in the area of security problems The system is the back-traditional security tools difficult to take into account.Firewall is difficult to take into account the type of security issues in most casesthese intrusions can legitimately through the firewall and difficult to detect Forexample the well-known ASP source issue in the IIS Server 4.0 has been previouslyexist it is IIS services of a designer left the back door no one can use the browserfrom the network to facilitate the transfer of the ASP program source code which cancollect information systems which attack the system. For this type of invasion thefirewall can not be perceived as a firewall for example the act of invasion and thenormal course of the visit of the visit was similar to the Web the only difference isthat the invasion of the visit to link the request to add a suffix.e As long as there are procedures that may exist on the BUG As long as there are procedures that may exist on the BUG. Even the securitytools also possible security loopholes. Almost every day a new BUG was found andpublished in the process to amend the designer known for BUG at the same time itmay have had a new BUG. BUG system hackers often use and this attack does notnormally have a log almost no data are available. For example many programs theexistence of the memory overflow BUG and safe use of these tools for BUGs almostimpossible to guard against attacks.f hacking efforts Almost every day a different system security problems. Means hackers areconstantly updated and security tools to update the rate lagged far behind the attacksmeans the update rate the vast majority of cases people need to be able to participatein the discovery of previously unknown security issues making their impact onemerging security The question is always too slow in responding. When the securitytools to detect and correct just a safety issue other security issues have emerged. As aresult hackers can always use advanced security tools can not find the means to carryout attacks.Second the networks vulnerability has led to arbitrary hackers onthe Internet Hang According to the Warroon Research survey inλ 1997 the worlds top 1000companies have been almost hackers broke into. According to FBI statistics of the United States the United States each year as aresult of network security caused by the loss of up to 7500000000 U.S. dollars. Ernst and Young report due to theft or misuse of informationλ security almost80 of large enterprises suffered losses In a recentλ large-scale hacker attacks the Yahoo Web site to stop running 3hours so the loss of millions of dollars of transactions. According to stati.