• Title, Summary, Keyword: Regular Expression

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Design and Implementation of a Host Interface for a Regular Expression Processor (정규표현식 프로세서를 위한 호스트 인터페이스 설계 및 구현)

  • Kim, JongHyun;Yun, SangKyun
    • KIISE Transactions on Computing Practices
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    • v.23 no.2
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    • pp.97-103
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    • 2017
  • Many hardware-based regular expression matching architectures have been proposed for high-performance matching. In particular, regular expression processors, which perform pattern matching by treating the regular expressions as the instruction sequence like general purpose processors, have been proposed. After instruction sequence and data are provided in the instruction memory and data memory, respectively, a regular expression processor can perform pattern matching. To use a regular expression processor as a coprocessor, we need the host interface to transfer the instruction and data into the memory of a regular expression processor. In this paper, we design and implement the host interface between a host and a regular expression processor in the DE1-SoC board and the application program interface. We verify the operations of the host interface and a regular expression processor by executing the application programs which perform pattern matching using the application program interface.

A Regular Expression Matching Algorithm Based on High-Efficient Finite Automaton

  • Wang, Jianhua;Cheng, Lianglun;Liu, Jun
    • Journal of Computing Science and Engineering
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    • v.8 no.2
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    • pp.78-86
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    • 2014
  • Aiming to solve the problems of high memory access and big storage space and long matching time in the regular expression matching of extended finite automaton (XFA), a new regular expression matching algorithm based on high-efficient finite automaton is presented in this paper. The basic idea of the new algorithm is that some extra judging instruments are added at the starting state in order to reduce any unnecessary transition paths as well as to eliminate any unnecessary state transitions. Consequently, the problems of high memory access consumption and big storage space and long matching time during the regular expression matching process of XFA can be efficiently improved. The simulation results convey that our proposed scheme can lower approximately 40% memory access, save about 45% storage space consumption, and reduce about 12% matching time during the same regular expression matching process compared with XFA, but without degrading the matching quality.

Architecture for Efficient Character Class Matching in Regular Expression Processor (정규표현식 프로세서에서의 효율적 문자 클래스 매칭을 위한 구조)

  • Yun, SangKyun
    • Journal of IKEEE
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    • v.22 no.1
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    • pp.87-92
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    • 2018
  • Like CPUs, regular expression processors that perform regular expression pattern matching using instructions have been proposed recently. Of these, only REMPc provides features for character class matching. In this paper, we propose an architecture for efficient character class matching in a regular expression processor, which use character class bitmap format in a instruction operand field and implement the hard-wired character class comparator for several frequently used character classes. Using the proposed method, most of the character classes used in Snort rule can be represented by an operand or an instruction. Thus, character class matching can be performed more efficiently in the proposed archiecture than in REMPc.

On the regular expression of the node-significant sequential graph (점의미형(點意味型) 순서도(順序圖)의 정규표현(正規表現)에 관(關)한 연구(硏究))

  • Kim, Hyeon-Jae
    • Proceedings of the KIEE Conference
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    • pp.486-489
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    • 1986
  • The transition diagram, as well as the regular expression, can be used as a formal description for a language acceptable by a finite automaton or for the behavior of a sequential switching circuit. But, if we are given one of these two descriptions, we shall find that it is not easy to get the other counterpart description. This paper is to show an easy method to find the equivalet regular expression from the transition diagram, by the aid of a graph-transformation technique.

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A Hardware Architecture of Regular Expression Pattern Matching for Deep Packet Inspection (심층 패킷검사를 위한 정규표현식 패턴매칭 하드웨어 구조)

  • Yun, Sang-Kyun;Lee, Kyu-Hee
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.5
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    • pp.13-22
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    • 2011
  • Network Intrusion Detection Systems use regular expression to represent malicious packets and hardware-based pattern matching is required for fast deep packet inspection. Although hardware architectures for implementing constraint repetition operators such as {10} were recently proposed, they have some limitation. In this paper, we propose hardware architecture supporting constraint repetitions of general regular expression sub-patterns with lower logic complexity. The subpatterns supported by the proposed contraint repetition architecture include general regular expression patterns as well as a single character and fixed length patterns. With the proposed building block, we can implement more efficiently regular expression pattern matching hardwares.

INTUITIONISTIC FUZZY AUTOMATA AND INTUITIONISTIC FUZZY REGULAR EXPRESSIONS

  • Choubey, Alka;K M, Rayi
    • Journal of applied mathematics & informatics
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    • v.27 no.1_2
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    • pp.409-417
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    • 2009
  • A definition of finite automaton (DFA and NDFA) with intuitionistic fuzzy (final) states is proposed. Acceptance of intuitionistic fuzzy regular language by the finite automaton (DFA and NDFA) with intuitionistic fuzzy (final) states are examined. It is found that the finite automaton (DFA and NDFA) with intuitionistic fuzzy (final) states is more suitable for recognizing intuitionistic fuzzy regular language than earlier model. The paper also gives an idea of intuitionistic fuzzy regular expressions through possible definitions.

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A Hardware Architecture of Multibyte-based Regular Expression Pattern Matching for NIDS (NIDS를 위한 다중바이트 기반 정규표현식 패턴매칭 하드웨어 구조)

  • Yun, Sang-Kyun;Lee, Kyu-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.1B
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    • pp.47-55
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    • 2009
  • In recent network intrusion detection systems, regular expressions are used to represent malicious packets. In order to process incoming packets through high speed networks in real time, we should perform hardware-based pattern matching using the configurable device such as FPGAs. However, operating speed of FPGAs is slower than giga-bit speed network and so, multi-byte processing per clock cycle may be needed. In this paper, we propose a hardware architecture of multi-byte based regular expression pattern matching and implement the pattern matching circuit generator. The throughput improvements in four-byte based pattern matching circuit synthesized in FPGA for several Snort rules are $2.62{\sim}3.4$ times.

Mining Regular Expression Rules based on q-grams

  • Lee, Inbok
    • Smart Media Journal
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    • v.8 no.3
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    • pp.17-22
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    • 2019
  • Signature-based intrusion systems use intrusion detection rules for detecting intrusion. However, writing intrusion detection rules is difficult and requires considerable knowledge of various fields. Attackers may modify previous attempts to escape intrusion detection rules. In this paper, we deal with the problem of detecting modified attacks based on previous intrusion detection rules. We show a simple method of reporting approximate occurrences of at least one of the network intrusion detection rules, based on q-grams and the longest increasing subsequences. Experimental results showed that our approach could detect modified attacks, modeled with edit operations.

Classification of Peroxiredoxin Subfamilies Using Regular Expressions

  • Chon, Jae Kyung;Choi, Jongkeun;Kim, Sang Soo;Shin, Whanchul
    • Genomics & Informatics
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    • v.3 no.2
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    • pp.55-60
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    • 2005
  • Peroxiredoxins (Prx's) are a superfamily of peroxidases that are ubiquitous in all super-kingdoms. Previous biochemical and structural studies have suggested that Prx's could be divided into five subfamilies (1-Cys, Typical 2-Cys, Atypical 2-Cys C-, L- and R- types). In this work, we have developed a set of regular expression patterns describing subfamily-specific spatial constraints of the key catalytic residues. Using these patterns, 1,016 Prx's available in public databases were classified into the five subfamilies. Our method performed well for most of the types except for Atypical 2 Cys R type.

Development of the Pattern Matching Engine using Regular Expression (정규 표현식을 이용한 패턴 매칭 엔진 개발)

  • Ko, Kwang-Man;Park, Hong-Jin
    • The Journal of the Korea Contents Association
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    • v.8 no.2
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    • pp.33-40
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    • 2008
  • In various manners, string pattern matching algorithm has been proven for prominence in speed of searching particular queries and keywords. Whereas, the existing algorithms are limited in terms of various pattern. In this paper, regular expression has been utilized to improve efficiency of pattern matching through efficient execution towards various pattern of queries including particular keywords. Such as this research would enable to search various harmful string pattern more efficiently, rather than matching simple keywords, which also implies excellent speed of string pattern matching compared to that of those existing algorism. In this research, the proposed string search engine generated from the LEX are more efficient than BM & AC algorithm for a string patterns search speed in cases of 1000 with more than patterns, but we have got similar results for the keywords pattern matching.