Intrusion detection method using adaptive rule estimation in nids

An intrusion detection method by adaptive rule estimation in a network-based intrusion detection system (NDS) is disclosed. The method includes collecting a packet on a network and searching for an original rule most similar to the collected packet from a rule database in which a rule for intrusion detection is stored, and judging whether a hacker intrudes by estimating a changed position of the collected packet from the original rule. Accordingly, it is possible to prevent an indirect attack of a hacker using a packet whose number of bits is changed due to deletion/insertion of characters from/into the packet.