Design Of Intrusion Detection System And Its Realization

With the development and ever widening application of network technology, information processing tends to be more dependent on networks. Information infrastructure has been an important supporting point of the national economy. Therefore, as a significant part of the information infrastructure, information security is associated with the nation survival, economical development, and social stability. With the network attacking instruments and techniques complicating and diversifying, the traditional network security alert techniques can hardly satisfy the network security requirement. As a result, network security study serves as a most significant task at present. And Intrusion Detection System (IDS) is a new yet fast developing network security technique in recent years.With a view to information security technique, this essay presents the popular categories of IDS and their definitions in detail. In addition, it also introduces the security techniques adopted by IDS, the pattern matching technique, and makes clear the merit and defect of it.Following the discussion of IDS, the third chapter gives a particular introduction to a complete IDS design, which is realized by combining the inside and outside IDS (the outside one is based on pattern matching, while the inside one relies on tactic), overcoming the defect of pattern matching technique. Meanwhile, the method of designing the system detection rule is elicited through the analysis of the Synscan scanning instrument feature data; and the realization of the corresponding code when detecting variation attack is expounded in details. In addition, a full analysis on its spreading feature is conducted by a case study on detecting Nimda virus, and the complete code is included in the design.In the fourth chapter, the conclusion is made on the IDS project, with the shortage and improvement to be made being put forward. Meanwhile, the importance of security awareness is emphasized in network security.