Abstract Community detection plays a key role in such important fields as biology, sociology and computer science. For example, detecting the communities in proteinprotein interactions networks helps in understanding their functionalities. Most existing approaches were devoted to community mining in undirected social networks (either weighted or not). In fact, despite their ubiquity, few proposals were interested in community detection in oriented... Community detection plays a key role in such important fields as biology, sociology and computer science. For example, detecting the communities in proteinprotein interactions networks helps in understanding their functionalities. Most existing approaches were devoted to community mining in undirected social networks (either weighted or not). In fact, despite their ubiquity, few proposals were interested in community detection in oriented social networks. For example, in a friendship network, the influence between individuals could be asymmetric; in a networked environment, the flow of information could be unidirectional. In this paper, we propose an algorithm, called ACODIG, for community detection in oriented social networks. ACODIG uses an objective function based on measures of density and purity and incorporates the information about edge orientations in the social graph. ACODIG uses ant colony for its optimization. Simulation results on real-world as well as power law artificial benchmark networks reveal a good robustness of ACODIG and an efficiency in computing the real structure of the network. Read More Read Less

Abstract Storage area networks is among the solutions that have been deployed in most enterprise information systems through the world by ensuring the processing of corporate data taking benefit of the high speed and the separation of provided services from processed data. Due to the great need of such infrastructures, a wireless connectivity have been added to these networks in order... Storage area networks is among the solutions that have been deployed in most enterprise information systems through the world by ensuring the processing of corporate data taking benefit of the high speed and the separation of provided services from processed data. Due to the great need of such infrastructures, a wireless connectivity have been added to these networks in order to ensure more flexibility and mobility for interconnected components in order to deal with environment constraints in addition to advanced security strategies defined for critical services and data and that have lead to a new kind of networks called wireless storage area networks. Such emerging networks integrate in most cases transaction- based applications that are exposed to several security threats that aim to prevent the correct processing of transactions and engender damage to interconnected components. In this paper, we propose a novel intrusion tolerant transaction management model for wireless storage area networks. The proposed model defines the secure flex transaction concept and is based on intrusion and detection strategy and compensability feature to manage transactions in WSAN either if this environment is compromised. Moreover, this model uses the Predicate Transition Net as a tool to control the executability of secure flex transactions. In order to illustrate the behavior of the proposed model and their security capabilities, a case study is defined for a transaction-based e-payment service for an online commerce company integrated in a monitored wireless storage area network that is exposed to a set of security attacks. Read More Read Less

Abstract Wormhole attack is one of the most severe threats against multi-hop wireless sensor networks. An attacker can easily prevent a normal network from collecting information. Most existing methods have difficulty in finding out the wormhole accomplice nodes or obtain a high detection success rate. In this work, we propose a novel detection mechanism. Our method requires only a small number... Wormhole attack is one of the most severe threats against multi-hop wireless sensor networks. An attacker can easily prevent a normal network from collecting information. Most existing methods have difficulty in finding out the wormhole accomplice nodes or obtain a high detection success rate. In this work, we propose a novel detection mechanism. Our method requires only a small number of anchor nodes. Using these anchor nodes disposed in a network, we can get many links among nodes for detecting the existence of a wormhole channel quickly. A node matching algorithm based on the links is proposed to find out the wormhole nodes. For a hidden wormhole attack, a traffic analysis algorithm based on the links is proposed to distinguish the infected area nodes which locate around wormhole nodes. Finally, our wormhole detection method is evaluated to be efficient by experiments. Read More Read Less

Abstract With the increase in population, vehicle traffic has also increased on roads; which have caused an increase in accidents, due to which many people have lost their lives and millions are injured annually. Hence, a foolproof and secure Vehicular Adhoc Network (VANET) structure is required to reduce the number of accidents considerably. In this paper, a VANET structure has been... With the increase in population, vehicle traffic has also increased on roads; which have caused an increase in accidents, due to which many people have lost their lives and millions are injured annually. Hence, a foolproof and secure Vehicular Adhoc Network (VANET) structure is required to reduce the number of accidents considerably. In this paper, a VANET structure has been proposed for highways and urban environments. In the Highway model, separate Road Side Units have been provided for the traffic on each side. In this way group formation for localized traffic will be easy on highways. Simulation results show that by using proposed model, average Throughput and End-to- End delay are improved considerably while packet loss has also been reduced. Read More Read Less