Patent · US Expired

Methods and systems for multi-pattern searching

US7539681B2 · kind B2 · utility

24Cited by
53References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 26, 2004
Grant dateMay 26, 2009
Priority date
Expiry dateAug 23, 2025

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S707/99939
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Embodiments of the present invention relate to systems and methods for optimizing and reducing the memory requirements of state machine algorithms in pattern matching applications. Memory requirements of an Aho-Corasick algorithm are reduced in an intrusion detection system by representing the state table as three separate data structures. Memory requirements of an Aho-Corasick algorithm are also reduced by applying a banded-row sparse matrix technique to the state transition table of the state table. The pattern matching performance of the intrusion detection system is improved by performing a case insensitive search, where the characters of the test sequence are converted to uppercase as the characters are read. Testing reveals that state transition tables with sixteen bit elements outperform state transition tables with thirty-two bit elements and do not reduce the functionality of intrusion detection systems using the Aho-Corasick algorithm.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.