Abstract: Pattern matching is an important algorithm in intrusion detection system．The efficiency of this algorithm directly affects the intrusion detection system's performance. As in the process of traditional pattern matching algorithm, matches were done according to the character order in the pattern, a pattern matching algorithm based on statistics was proposed. By using the statistical characteristics of the string itself, the algorithm chooses the least frequency substring's characters in the main string as the key characters. According to this characters' position in the main string, jump matching are done. Thus the speed of pattern matching was accelerated greatly. The experiment results show that this algorithm is more efficient than other similar algorithms.

Key words: Pattern matching , ntrusion detection system , Statistical , Frequency

摘要： 模式匹配算法是入侵检测系统中的一种重要算法,算法的效率直接影响入侵检测系统的性能。针对
传统模式匹配算法按照模式中字符排列顺序进行匹配的过程,提出一种基于统计的模式匹配算法,该算法利用字符
串本身的统计特征,利用子串中在主串中出现频率最少的字符为关键字符,通过该字符在主串中出现的位置进行跳
跃式匹配,加快了模式匹配的速度。实验结果表明,该算法比同类的其它算法更加高效。

关键词: 模式匹配 , 入侵检测系统 , 统计 , 频率