Even though it is an essential requirement of any computer system, there is not yet a standard method to measure data security, especially when sending information over a network. However, the most common technique used to achieve the three goals of security is encryption. Three security metrics are derived from important issues of network security in this chapter. Each metric demonstrates the level of achievement in preserving one of the security goals. Routing algorithms based on these metrics are implemented to test the proposed solution. Computational effort and blocking probability are used to assess the behavior and the performance of these routing algorithms. Results show that the algorithms are able to find feasible paths between communicating parties and make reasonable savings in the computational effort needed to find an acceptable path. Consequently, higher blocking probabilities are encountered, which is the price to be paid for such savings. arabic 3 English 22
Ibrahim Almerhag(3-2014)

DLFSR is promising for enhancing the security of stream ciphers. However, good inviolability and statistical properties of the DLFSR generator are only achievable when the parameters of the switching algorithm are properly selected. This paper describes a new experimental method for choosing suitable parameters for the algorithm of switching the polynomial in DLFSR. This method was used to enhance the Grain-128 stream cipher. The randomness of the modified Grain was evaluated using the NIST suite, and the results are encouraging. The modified Grain was also compared to the original, and the results indicated that the modified algorithm outperforms the original in several tests. arabic 12 English 82
Fayrouz Aljadi, Ibrahim Almerhag, Fardous Eljadi(3-2019)

In this paper a brief introduction to the concept of quality of service has been given. However, it mainly focuses on the classification of routing algorithms based on a number of different criteria like: protocols, structure, technologies in use, etc. And it concludes with a presentation of a common problem facing routing protocols, namely routing loops, and explained the known solutions to that problem. arabic 6 English 52
Ibrahim Almerhag, Ali Ganoun(6-2018)

A performance evaluation of sound recognition techniques in recognizing some spoken Arabic words, namely digits from zero to nine, is proposed. One of the main characteristics of all Arabic digits is polysyllabic words except for zero. The performance analysis is based on different features of phonetic isolated Arabic digits. The main aim of this paper is to compare, analyze, and discuss the outcomes of spoken Arabic digits recognition systems based on three recognition features: the Yule-Walker spectrum features, the Walsh spectrum features, and the Mel frequency Cepstral coefficients (MFCC) features. The MFCC based recognition system achieves the best average correct recognition. On the other hand, the Yule-Walker based recognition system achieves the worst average correct recognition. arabic 7 English 60
A. Ganoun, I. Almerhag(6-2012)

in wireless networks, mobility is an important issue because Internet connectivity can only be effective if it is available during the movement of a node. To enhance mobility, the IEEE802.16e standard has set procedures to design wireless access systems to operate on the move without any disruption of services. The major difference between mobile WiMAX and fixed WiMAX is mobility support. However, speed and trajectory of nodes are unpredictable and can vary even in identical circumstances. In this paper mobile node trajectory is studied under different codecs schemes in order to evaluate the effect of node movement, towards or away from the base-station, on end to end delay, jitter, mean opinion score and throughput of a VoIP application. The results showed that trajectory inward improves network performance since mobile node gets closer to the base-station and hence signal is improved and less power is required. arabic 12 English 67
I. Almerhag, N. Aboalgasem(5-2017)