Performance Study of the Running Times of well known Pattern Matching Algorithms for Signature-based Intrusion Detection Systems

Intrusion detection system (IDS) is the basic component of any network defense scheme. Signature based intrusion detection techniques are widely used in networks for fast response to detect threats. One of the main challenges faced by signature-based IDS is that every signature requires an entry in the database, and so a complete database might contain hundreds or even thousands of entries. Each packet is to be compared with all the entries in the database. This can be highly resource-consuming and doing so will slow down the throughput and making the IDS vulnerable. Since pattern matching computations dominate in the overall performance of a Signature-based IDS, efficient pattern matching algorithms should be used which use minimal computer storage and which minimize the searching response time. In this paper we present a performance study of the running times of different well known pattern matching algorithms using multiple sliding windows approach. DOI: 10.17762/ijritcc2321-8169.150613

Implementation of Pattern Matching Algorithm for Multimedia Files in Mail Function Detection

Now a days internet and mail based file transfer has increased enormously due to this server space required will be highly and also occurs largely. In existing system if we upload the same file which is present in the server also get uploaded and duplication occurs. We used a pattern matching algorithm it eliminate duplication and also to avoid time wastage in uploading the same file present in the server. During file upload pattern will be matched. If pattern matched file won't be uploaded again it will simply matched the existing file it avoids uploading the file again. If pattern doesn't match it allow uploading the file. From this we save the memory space in the server and duplication doesn't occur

Implementation and comparison of Berry-Ravindran and Zhu- Takaoka exact string matching algorithms in Indonesian-Batak Toba dictionary

Indonesia has a variety of local languages, which is the Batak Toba language. This time, there are still some Batak Toba people who do not know speak Batak Toba language fluently. Nowadays, desktop based dictionary is one of reference that very efficiently used to learn a language and also to increase vocabulary. In making the dictionary application, string matching can be implemented for word-searching process. String matching have some algorithm, which is Berry – Ravindran algorithm and Zhu-Takaoka algorithm and will be implemented on the dictionary application. Zhu-Takaoka algorithm and Berry – Ravindran algorithm have two phases, which are the preprocessing phase and the searching phase. Preprocessing phase is a process to make the shifting values according to in pattern that input by user. To know the shifting value with Zhu-Takaoka algorithm, it’s need Zhu-Takaoka Bad Character (Ztbc) and Boyer-Moore Good Suffix (Bmgs). Then, Ztbc will be compared to Bmgs to get the maximum value of them that will be set as shifting value. While Berry-Ravindran algorithm, to know the shifting value is needed Berry-Ravindran Bad Character, which the two characters right of the text at the position m + 1 and m+ 2, is needed to determine the shifting value, where m is length of the pattern

Menghitung Ketepatan Jawaban Soal Ujian Essay dengan Penerapan Algoritma Boyer-Moore

Pendidikan memegang peranan penting dalam mempersiapkan mahasiswanya menjadi sumber daya manusia yang berkualitas. Untuk mengukur prestasi belajar seorang mahasiswa perlu dilakukan sebuah tes atau ujian untuk menguji setiap mata kuliah yang telah dilakukan pada saat proses belajar mengajar. Jenis tes pun ada beberapa macam, seperti tes tertulis, tes lisan, dan tes praktek. Pada tes tertulis pun terdapat beberapa jenis soal, salah satunya adalah soal berbentuk essay. Soal essay adalah soal dimana mahasiswa harus menjawab soal dengan kalimat yang diingat atau dibuat sendiri, hal tersebut membuat kemungkinan munculnya jawaban dengan variasi yang banyak sangat tinggi, hal ini membuat dosen membutuhkan waktu dan tenaga yang banyak. Diperlukannya sebuah sistem yang bisa digunakan oleh dosen untuk mengetahui ketepatan jawaban soal essay. Algoritma Boyer-Moore adalah algoritma yang digunakan untuk pencarian string dengan pola pencarian dari kanan ke kiri, Algoritma Boyer-Moore dianggap sebagai algoritma pencocokan string yang paling efisien dalam aplikasi-aplikasi yang biasa digunakan, seperti aplikasi text editor untuk fungsi “search” dan “subtitute”. Penelitian ini menerapkan algoritma Boyer-Moore untuk mencari kunci jawaban yang dosen anggap benar pada jawaban mahasiswa dengan cara dosen menginputkan kunci jawaban secara utuh lalu akan dipecah menjadi perkata dan dosen memberi poin pada setiap kata untuk dihitung sebagai nilai. Mahasiswa hanya perlu menginputkan jawaban yang dianggap benar dan algoritma Boyer-Moore akan mencari kunci jawaban yang diinputkan oleh dosen pada jawaban mahasiswa. Output yang dihasilkan akan berupa persentase ketepatan per soal dan nilai seluruh mahasiswa yang mengikuti mata kuliah. Hasil dari kuesioner yang disebarkan kepada dosen dan ahli sistem menunjukkan hasil sangat layak pada kedua responden

Optimal-Hash Exact String Matching Algorithms

String matching is the problem of finding all the occurrences of a pattern in a text. We propose improved versions of the fast family of string matching algorithms based on hashing $q$-grams. The improvement consists of considering minimal values $q$ such that each $q$-grams of the pattern has a unique hash value. The new algorithms are fastest than algorithm of the HASH family for short patterns on large size alphabets.Comment: 14 page

Signal Analysis on Strings for Immune-Type Pattern Recognition

We use wavelet-type discrete transforms for signal analysis on strings of finite length. We apply these transforms for edge and hidden Markov process detection. We also present new approaches for string matching and for measures of the diversity of chaotic strings

The Swap Matching Problem Revisited

In this paper, we revisit the much studied problem of Pattern Matching with Swaps (Swap Matching problem, for short). We first present a graph-theoretic model, which opens a new and so far unexplored avenue to solve the problem. Then, using the model, we devise two efficient algorithms to solve the swap matching problem. The resulting algorithms are adaptations of the classic shift-and algorithm. For patterns having length similar to the word-size of the target machine, both the algorithms run in linear time considering a fixed alphabet.Comment: 23 pages, 3 Figures and 17 Table