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Pocket Switched Network (PSN) is a branch of Delay Tolerant Network (DTN) which is intended to work in a challenged network. Challenged network is network with lack of infrastructure such as disaster area. As such, the network has intermittent connectivity. PSN provides a new paradigm to distribute messages in the network by taking advantage of roaming nodes from one place to another. In this paper, network performances of eight PSN routing protocols are investigated namely, First Contact, Direct Delivery, Epidemic, PRotocol using History of Encounter and Transitivity (PRoPHET), Spray and Wait, Binary Spray and Wait, Fuzzy Spray, Adaptive Fuzzy Spray and Wait. The performance metrics are packet delivery ratio, overhead ratio and average latency. Opportunistic Network Environment (ONE) simulator is used to evaluate the network performance. Experiments show that Epidemic has the best performance in term of message delivery ratio, but it has the highest overhead ratio. Direct Delivery has the lowest overhead ratio (zero overhead ratio) and PRoPHET has the lowest latency average.

Detection accuracy of Intrusion Detection System (IDS) depends on classifying network traffic based on data features. Using all features for classification consumes more computation time and computer resources. Some of these features may be redundant and irrelevant therefore, they affect the detection of traffic anomalies and the overall performance of the IDS. The literature proposed different algorithms and techniques to define the most relevant sets of features of KDD cup 1999 that can achieve high detection accuracy and maintain the same performance as the total data features. However, all these algorithms and techniques did not produce optimal solutions even when they utilized same datasets. In this paper, a new approach is proposed to analyze the researches that have been conducted on KDD cup 1999 for features selection to define the possibility of determining effective generic features of the common dataset KDD cup 1999 for constructing an efficient classification model. The approach does not rely on algorithms, which shortens the computational cost and reduces the computer resources. The essence of the approach is based on selecting the most frequent features of each class and all classes in all researches, then a threshold is used to define the most significant generic features. The results revealed two sets of features containing 7 and 8 features. The classification accuracy by using eight features is almost the same as using all dataset features.

Vehicle Ad hoc Network (VANET) is an emerging and promising technology for the Intelligent Transportation System (ITS). VANET can help to increase safety and traffic efficiency in flexible and feasible way. However, disseminating incorrect information in VANET has wide range of implications effecting drivers’ behaviors and causing serious, and may be catastrophic, results. Misbehaving attackers can create traffic illusion to disturb VANET operations as well as the potential deployment of safety and traffic efficiency applications. In this paper, a holistic view of the existing misbehavior detection approaches for countermeasures against spreading malicious data in VANET is studied. In addition, the importance and the challenges faced when verifying the correctness of VANET messages are discussed. Finally, the drawbacks of existing detection and verification approaches are analyzed.

Printed documents are still relevant in our daily life and information in it must be protected from threats and attacks such as forgery, falsification or unauthorized modification. Such threats make the document lose its integrity and authenticity. There are several techniques that have been proposed and used to ensure authenticity and originality of printed documents. But some of the techniques are not suitable for public use due to its complexity, hard to obtain special materials to secure the document and expensive. This paper discuss several techniques for printed document security such as watermarking and barcode as well as the usability of two dimensional barcode in document authentication and data compression with the barcode. A conceptual solution that are simple and efficient to secure the integrity and document sender’s authenticity is proposed that uses two dimensional barcode to carry integrity and authenticity information in the document. The information stored in the barcode contains digital signature that provides sender’s authenticity and hash value that can ensure the integrity of the printed document.

Kertas kerja ini mencadangkan pengoptimuman langkah penawanan paket di dalam algoritma pengesanan batu loncatan yang boleh memendekkan masa tindak balas keseluruhan mekanisma penindakbalasan. Tujuan penyelidikan ini adalah bagi membuktikan langkah penawanan paket di dalam algoritma batu loncatan seterusnya membolehkan percepatan penindakbalasan bahagian penindakbalasan daripada keseluruhan sistem pengesanan dan penindakbalasan. Kaedah yang dicadangkan diperkenalkan dengan menggunakan saiz penimbal pengguna dan penimbal kernel yang kecil. Eksperimen dijalankan dengan menggunakan dua jenis aliran paket rangkaian; i) 10 kbps dan ii) 10 000 kbps yang dijana menggunakan perkakasan Tfgen (penjana paket) dan kombinasi sembilan saiz penimbal yang berbeza untuk setiap aliran paket rangkaian yang diuji. Keputusan daripada eksperimen dianalisa. Daripada keputusan, kaedah yang dicadangkan (dengan menggunakan saiz penimbal yang kecil) memberikan keputusan yang lebih baik. Penyelidikan ini menyimpulkan bahawa dengan menggunakan kaedah yang dicadangkan, masa tindak balas dapat diperbaiki. Kata kunci: IDS, IRS, pengesanan batu loncatan, jurang masa, pengoptimuman This paper proposes an optimized packet capturing stone detection algorithm that can shorten the response time of overall response mechanism. The aim of the research is to improve the packet capturing step in stepping stone algorithm, thus, improve the response from overall detection and response system. The proposed method is to use small size of user buffer and kernel buffer. Experiments were conducted with two types of packet stream; i) 10 kbps and ii) 10 000 kbps data generated by Tfgen (packet generator) tools and nine combinations of different buffer sizes for each network packet stream were tested. Results from the experiment were analyzed. From the result, it is proven that the proposed method (by using small size of buffer) gives better result. The research concludes that by using the proposed method, the response time can be improved. Key words: IDS, IRS, detecting stepping stones, time gap, optimization