Search

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Satellite networks are recognized as the most essential communication infrastructures in the world today, which complement land networks and provide valuable services for their users. Extensive coverage and service stability of these networks have increased their popularity. Since eavesdropping and active intrusion in satellite communications are much easier than in terrestrial networks, securing satellite communications is vital. So far, several protocols have been proposed for authentication and key exchange of satellite communications, but none of them fully meet the security requirements. In this paper, we examine one of these protocols and identify its security vulnerabilities. Moreover, we propose a robust and secure authentication and session key agreement protocol using the elliptic curve cryptography (ECC).We show that the proposed protocol meets common security requirements and is resistant to known security attacks. Moreover, we prove that the proposed scheme satisfies the security features using the Automated Validation of Internet Security Protocols and Applications (AVISPA) formal verification tool and On-the fly Model-Checker (OFMC) and ATtack SEarcher (ATSE) model checkers. We have also proved the security of the session key exchange of our protocol using the Real or Random (RoR) model. Finally, the comparison of our scheme with similar methods shows its superiority. [ABSTRACT FROM AUTHOR]

Software‐defined networks are a modern architecture in computer networks where traffic transfer is separated from network control. In software‐defined networks, all decisions are made in the controller, and the necessary commands are injected into the network equipment. With the advent of software‐defined networks and the introduction of a new concept called controller in these types of networks, it becomes important to find an appropriate location for the controller and its number in the network. This problem aims to find the location and the optimal number of controllers needed in the network, and how to assign switches to the controllers declined certain constraints. In this article, a method to determine the appropriate location for controllers is proposed, so that the cost of network implementation would be reduced and thus its survivability is improved. Finally, we analyzed the proposed method in terms of evaluation criteria. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the downside characteristics of Mobile Ad hoc Networks (MANETs) such as dynamic topology and energy consumption and control overhead, network clustering is one of the promising solutions. Cluster Based Routing Protocol (CBRP) is a robust and scalable routing protocol for MANETs. Clustering formation algorithm used in CBRP is a variation of simple lowest-ID algorithm in which the node with a lowest ID among its neighbors is elected as the Cluster head. Neglecting mobility and energy for selecting cluster head is one of the weakness points of the algorithm. In order to increase stability of the network and to prevent re-clustering an adaptive energy-aware Cluster Based Routing Protocol (AECBRP) is proposed. Two algorithms have been introduced in AECBRP as enhancement to the CBRP: improving the cluster formation algorithm by considering relative mobility, residual energy and connectivity degree metrics, and add in an efficient cluster maintenance algorithm based on the aggregate energy metric of cluster head. Using NS-2 we evaluate the rate of cluster-head changes, the normalization routing overhead and the packet delivery ratio. Comparisons denote that the proposed AECBRP has better performances with respect to the original CBRP and Cross-CBRP. [ABSTRACT FROM AUTHOR]