1 / 16

Optimization of Regular Expression Pattern Matching Circuits on FPGA

Optimization of Regular Expression Pattern Matching Circuits on FPGA. Authors : Cheng-Hung Lin, Chih-Tsun Huang, Chang-Ping Jiang, and Shih-Chieh Chang Publisher : Design,Automation and Test in Europe,2006.DATE’06 Proceedings Present: Kia-Tso Chang Date: November 15 2007. 1. outline.

joshua-hernandez
Télécharger la présentation

Optimization of Regular Expression Pattern Matching Circuits on FPGA

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Optimization of Regular Expression Pattern Matching Circuits on FPGA Authors: Cheng-Hung Lin, Chih-Tsun Huang, Chang-Ping Jiang, and Shih-Chieh Chang Publisher: Design,Automation and Test in Europe,2006.DATE’06 Proceedings Present: Kia-Tso Chang Date: November 15 2007 1

  2. outline • Introduction • Implementation of NFA • Sharing prefix common sub-patterns • Sharing scheme for infix and postfix

  3. Introduction In contrast to software-only NIDS, many studies proposed hardware architectures for accelerating attack detection Sidhu and Prasanna [1] proposed to construct an NFA (Nondeterministic Finite Automaton) from a regular expression to perform string matching. Hutchings, Franklin and Carver [2] developed a module generator that combined common prefixes to reduce FPGA area. 3

  4. Simple NFA and implementation in logic 4

  5. Regular expressions • Regular expressions are a common way to express attack patterns. • 1. The first type defines exact string patterns such as pattern, "Ahhhh My Mouth Is Open.” • 2. The second type consists of meta-characters

  6. Sharing prefix common sub-patterns

  7. An erroneous implementation to share infixDir

  8. Sharing scheme for infix and postfix

  9. An example of constraint 1 Abcdefgh defpq

  10. An example of constraint 2 abcdefgh dedefpq 10

  11. sharing gain • The sharing gain of a common sub-pattern is defined to be the number of characters in the sub-pattern multiplies by the number of regular expressions having the sub-pattern. For example, three regular expressions, “1Common1”, “2Common2”, and “3Common3” have the common sub-pattern “Common.” The sharing gain of the common sub-pattern is 18=6*3

  12. Flow of regular expression modulegeneration 12

  13. Logical structures for the proposedmeta-character components

  14. Logical structures for the proposedmeta-character components

  15. Implementation of NFA

  16. The comparison among different approaches on Snort rule sets

More Related