The International Arab Journal of 

Information Technology



January 2004, Volume 1, Number 1


Timing Attack Prospect for RSA Cryptanalysts Using Genetic Algorithm Technique

Hamza Ali and Mikdam Al-Salami

Computer Science Department, Zarka Private University, Jordan

 Abstract: This paper presents an approach to cryptanalysis of RSA cryptosystem based on the application of genetic algorithm. The search utilizes the idea of timing attack as computation time information may leak due to different modular operations throughout the RSA encoding. This approach suggests a speed up process, aiming at reducing the required number of plaintext-ciphertext samples needed for a successful timing attack. The proposed notion of timing attack outlined in this work with its preliminary implementation, have given encouraging results on RSA cryptosystem samples. Further work carried on to implement the idea of genetic algorithm technique to practical RSA system has demonstrated encouraging results.


Keywords: Cryptography, cryptanalysis, genetic algorithms, timing attacks, RSA, key search. 

 Received February 16, 2003; accepted June 26, 2003


Automatic Classification and Filtering of Electronic Information: Knowledge-Based Filtering Approach

Omar Nouali 1&2, Philippe Blache 2

1 Basic Software Laboratory, CERIST, Algérie

2 Laboratoire Parole et Langage, Université de Provence, France

 Abstract: In this paper we propose an artificial intelligent approach focusing on information filtering problem. First, we give an overview of the information filtering process and a survey of different models of textual information filtering. Second, we present our E-mail filtering tool. It consists of an expert system in charge of driving the filtering process in cooperation with a knowledge-based model. Neural networks are used to model all system knowledge. The system is based on machine learning techniques to continuously learn and improve its knowledge all along its life cycle. This email filtering tool assists the user in managing, selecting, classify and discarding non-desirable messages in a professional or non-professional context. The modular structure makes it portable and easy to adapt to other filtering applications such as web browsing. The performance of the system is discussed.


Keywords: Information filtering, expert systesms, machine learning, neural networks, relevance feedback, genetic algorithms.

 Received March 29, 2003; accepted July 20, 2003


A Generic Multimodal Architecture for Integrating Voice and Ink XML Formats

Zouheir Trabelsi

College of Telecommunication, The University of Tunisia, Tunisia


Abstract: The acceptance of a standard VoiceXML format has facilitated the development of voice applications, and we anticipate a similar facilitation of pen application development upon the acceptance of a standard InkXML format.  In this paper we present a multimodal interface architecture that combines standardized voice and ink formats to facilitate the creation of robust and efficient multimodal systems, particularly for noisy mobile environments.  The platform provides a Web interactive system for generic multimodal application development.  By providing mutual disambiguation of input signals and superior error handling this architecture should broaden the spectrum of users to the general population, including permanently and temporarily disabled users.  Integration of VoiceXML and InkXML provides a standard data format to facilitate Web based development and content delivery. Diverse applications ranging from complex data entry and text editing applications to Web transactions can be implemented on this system, and we present a prototype platform and sample dialogues. 


Keywords: Multimodal voice/ink applications, speech recognition, online handwriting recognition, mutual disambiguation, VoiceXML, InkXML.


Received March 13, 2003; accepted August 17, 2003



Virtual Rule Partitioning Method for Maintaining Database Integrity

Feras Hanandeh, Hamidah Ibrahim, Ali Mamat, and Rozita Johari

Faculty of Computer Science and Information Technology, University Putra Malaysia, Malaysia

 Abstract: The variant execution time of the update operation repair rules in a parallel and distributed environment is highly affected by the way the rules and tables settled in a database in according to whether they were partitioned or not. The well-known partitioning methods in the database were succeeded to reduce the response time of update operations since they expeditiously execute the update operation affecting different sites of partitions. These methods are mortgaged by the determination of the type of partitioning during the design state of the system fixing all sites of the partitioned tables and distributed rules to different nodes. Although distribution and partitioning have these merits, it still face some restrictions since it may be time consuming for the distributed system to locate the proper rule and the partition of data, which fulfill the requirement of repair update operation. This paper proposes virtual rule partition method. This method has more advantages over the classical methods because it allows us to reduce the total cost or the total response time consumed by repair update operations using horizontal partitioned tables.

 Keywords: Active database systems, database partitioning, semantic integrity maintenance.

 Received April 2, 2003; accepted August 10, 2003


Virtual Education Seriously Considered

Fawzi Al-Balooshi

Department of Computer Science, University of Bahrain, Kingdom of Bahrain

 Abstract: In recent years the use of computers and related technologies for education purposes has increased exponentially. Organizations from different sectors started to invest in educational software for learning, so did universities and other academic institutions. Research in this area has increased to explore the benefits that are possible through the use of computers to promote education. This paper explores the current practice in using educational software including the use of intelligent tutoring systems, virtual environments, technologies that can be used to develop educational software, authoring tools that can make the development of educational software a task for non-experts, and necessary evaluation procedures to ensure the educational benefits resulting from such software use.

Keywords: Virtual education, computer-based instruction, intelligent tutoring, authoring tools, evaluation.

 Received April 10, 2003; accepted June 15, 2003


A Data Base for Arabic Handwritten Text Recognition Research

Somaya Al-Ma’adeed, Dave Elliman, and Colin Higgins

  School of Computer Science and Information Technology, University of Nottingham, UK


 Abstract: In this paper we present a new database for off-line Arabic handwriting recognition, together with several preprocessing procedures. We designed, collected and stored a database of Arabic handwriting (AHDB). This resulted in a unique databases dealing with handwritten information from Arabic text, both in terms of the size of the database as well as the number of different writers involved. We further designed an innovative, simple, yet powerful, in place tagging procedure for the database. It enables us to extract at will the bitmaps of words. We also built a preprocessing class, which contains some useful preprocessing operations. In this paper, the most popular words in Arabic writing were found for the first time using a specially designed program.

Keywords: Arabic, handwriting, recognition, database, preprocessing, cursive script.

 Received April 15, 2003; accepted July 18, 2003


Configurable Hardware Implementations of Bulk Encryption Units for Wireless Communications

Paris Kitsos and Odysseas Koufopavlou

Electrical and Computer Engineering Department, University of Patras, Greece

 Abstract: Hardware implementations of bulk encryption units for wireless communications are presented in this paper. These units are based on the Triple DES (TDES) block cipher. The hardware modules can be configured in order to implement either the TDES or the DES block cipher. Three different hardware implementations of TDES are proposed. The first two implementations are based on the pipeline design technique, while the third implementation uses the traditional feedback logic design technique (looping). In addition, the DES block cipher’s S-BOXes have been implemented by Look Up Tables (LUTs) or ROM blocks. Comparing with the LUTs, the ROM blocks implementation approach provides higher performance. But, the LUTs implementation approach is used in cases where the ROM blocks are not available. For high-speed performance applications the loop unrolling architecture is selected. The proposed implementation of this architecture achieves 7.36 Gbps data throughput whilst the 16-stage pipeline 2.45 Gbps. The implementation data throughput which is based on the looping architecture is 121 Mbps, but is used significant less hardware resources.

 Keywords: Cryptography, triple-DES, DES, block cipher, S-Box, VLSI implementation.

 Received April 17, 2003; accepted August 3, 2003


Modeling of a Procedural Knowledge by a Dialogue Knowledge Base

Igor Chimir 1 and Waheeb Abu-Dawwas 2

1 Cherkassy Academy of Management, Ukraine

2 Computer Information Systems Department, Al-Zaytoonah University, Jordan

Abstract: This paper depicts theoretical results obtained in the line of projects related to constructing dialogue applications based on a formal cognitive model of a human-machine dialogue. One of the aims of the paper is to propose an appropriate model of question-answering dialogue, which can be used in designing relevant computer software. The theory proposes formal descriptions of declarative and procedural knowledge of dialogue’s agents and introduces the idea of a dialogue knowledge base, which is capable of storing the procedural and the declarative knowledge of dialogue’s agents. Emphasis on declarative-procedural typology of knowledge allows us to consider a dialogue process as a goal-oriented behavior; and, hence, as a general method of solving some classes of problems.

 Keywords: Human-machine dialogue, question-answering dialogue, logic of questions and answers, dialogue knowledge base, problem solving process.

 Received April 21, 2003; accepted July 27, 2003


Word Prediction via a Clustered Optimal Binary Search Tree

Eyas El-Qawasmeh

Computer Science Department, Jordan University of Science and Technology, Jordan

 Abstract: Word prediction methodologies depend heavily on the statistical approach that uses the unigram, bigram, and the trigram of words. However, the construction of the N-gram model requires a very large size of memory, which is beyond the capability of many existing computers. Beside this, the approximation reduces the accuracy of word prediction. In this paper, we suggest to use a cluster of computers to build an Optimal Binary Search Tree (OBST) that will be used for the statistical approach in word prediction. The OBST will contain extra links so that the bigram and the trigram of the language will be presented. In addition, we suggest the incorporation of other enhancements to achieve optimal performance of word prediction. Our experimental results showed that the suggested approach improves the keystroke saving.

 Keywords: Bigram, cluster computing, N-gram, unigram, trigram, word frequency, word prediction.

 Received April 21, 2003; accepted July 29, 2003


An Efficient Algorithm for the Generalized Partially Instantiated Same Generation Query in Deductive Databases

Nabil Arman

Palestine Polytechnic University, Palestine

 Abstract: The expressive power and intelligence of traditional database systems can be improved by recursion. Using recursion, relational database systems are extended into knowledge-base systems (deductive database systems). Linear recursion is the most frequently found type of recursion in deductive databases. In this paper, an algorithm to solve the generalized partially instantiated form of the same generation query in deductive databases is presented. The algorithm uses special data structures, namely, a special matrix that stores paths from roots of the graph representing a two-attribute normalized database relation to all nodes reachable from these roots, and a reverse matrix that stores paths from any node to all roots related to that node. Using simulation, this paper also studies the performance of the algorithm and compares that with the standard depth-first search based algorithms.

 Keywords: Deductive databases, linear recursive rules, same generation query.

 Received April 28, 2003; accepted July 22, 2003