Patent Document ID: 7539681
Application ID: 10898220
Patent Status: 1

Claim One:
1. A method for searching for search patterns in a text sequence using a state transition table of a state machine algorithm in an intrusion detection system, comprising: reading a character from the text sequence; reading an element of a current state vector of the state transition table that corresponds to the character; when the element has a nonzero value, checking a pattern matching element of the current state vector for a matching pattern flag; when the matching pattern flag is set, processing the matched patterns in the text sequence in an intrusion detection system to detect an intrusion; selecting the current state vector corresponding to the nonzero value of the element; reading a next character from the text sequence; checking an element of the current state vector that identifies a format; and when the format is banded, determining whether the character is in a band from an element of the current state vector identifying a number of elements in the band, an element of the current state vector identifying an index of a first element of the band, and elements of the band; then, when the character is in the band, selecting the current state vector corresponding to the nonzero value of the element; otherwise when the character is not in the band, returning the current state vector to an initial state; otherwise handling the character in accordance with a full vector format.