Wireless Lan Intrusion Detection System

Wireless local area network has developed very rapidly since the 1990s for it's many advantages, and at the same time, the security problem has become more and more remarkable.This paper firstly describes the characteristics of WLAN, protocol standards of IEEE802.11 series and the inherent vulnerability in the WLAN, then presents the common intrusion method, and at last, introduces the concept of intrusion detection, basic principles, work patterns, classification and trends, systematically. At the same time, this paper also describes the various key technologies of LAN intrusion detection system, and gives the conclusions that WLAN intrusion detection system is different from the wired in the design of intrusion detection systems through analysis and comparison.On the basis of analyzing WLAN and intension detection technique, this paper presents a model of wireless intrusion detection systems of the protocol analysis according to the characteristics of the wireless local area network. The pattern matching algorithm has the advantages of fast and simple computing and is used widely in practical applications. But the disadvantages are more CPU time and low detection accuracy. Combination of the above problems, we achieved good results by improving the pattern matching algorithm in this paper. Protocol network protocol analysis technology can take advantage of the high regularity of the presence of rapid attack detection. Through the hierarchy, the message formatting layer wireless network analysis can improve the efficiency of detection and effective control of false negative rate and false alarm rate.Finally, this paper gives the framework and the main process steps of the system, and presents a detailed design for the key modules. The system uses Winpcap library of wireless to capture the transmission data, then uses the decoding module to decode the pre-detection module by different protocol called analytic function on different levels. In the processing module, this paper uses a modular design. Based on actual needs of the situation corresponding increase, the analysis module finally gives the test data on the contents of the decoded rule matching to improve BM algorithm and to discover whether the system is compromised. Through theoretical analysis, the improved pattern matching algorithm is applied to intrusion detection based on protocol analysis system. The algorithm can also detect the popular wireless local area network invasion and provide the basic wireless network security.