The Impact of the Adversary's Eavesdropping Stations on the Location Privacy Level in Internet of Vehicles

The Internet of Vehicles (IoV) has got the interest of different research bodies as a promising technology. IoV is mainly developed to reduce the number of crashes by enabling vehicles to sense the environment and spread their locations to the neighborhood via safety-beacons to enhance the system functioning. Nevertheless, a bunch of security and privacy threats is looming; by exploiting the spatio-data included in these beacons. A lot of privacy schemes were developed to cope with the problem like CAPS, CPN, RSP, and SLOW. The schemes provide a certain level of location privacy yet the strength of the adversary, e.g., the number of eavesdropping stations has not been fully considered. In this paper, we aim at investigating the effect of the adversary’s eavesdropping stations number and position on the overall system functioning via privacy and QoS metrics. We also show the performances of these schemes in a manhattan-grid model which gives a comparison between the used schemes. The results show that both the number and the emplacement of the eavesdropping stations have a real negative impact on the achieved location privacy of the IoV users

Concepts and evolution of research in the field of wireless sensor networks

The field of Wireless Sensor Networks (WSNs) is experiencing a resurgence of interest and a continuous evolution in the scientific and industrial community. The use of this particular type of ad hoc network is becoming increasingly important in many contexts, regardless of geographical position and so, according to a set of possible application. WSNs offer interesting low cost and easily deployable solutions to perform a remote real time monitoring, target tracking and recognition of physical phenomenon. The uses of these sensors organized into a network continue to reveal a set of research questions according to particularities target applications. Despite difficulties introduced by sensor resources constraints, research contributions in this field are growing day by day. In this paper, we present a comprehensive review of most recent literature of WSNs and outline open research issues in this field

MMEDD: Multithreading Model for an Efficient Data Delivery in wireless sensor networks

Nowadays, the use of Wireless Sensor Networks (WSNs) is increasingly growing as they allow a large number of applications. In a large scale sensor network, communication among sensors is achieved by using a multihop communication. However, since the sensor is limited by its resources, sensors' operating systems are developed in order to optimize the management of these resources, especially the power consumption. Therefore, the hybrid operating system Contiki uses a low consumption layer called Rime which allows sensors to perform multihop sending with a low energy cost. This is favored by the implementation of lightweight processes called protothreads. These processes have a good efficiency/consumption ratio for monolithic tasks, but the management of several tasks remains a problem. In order to enable multitasking, Contiki provides to users a preemptive multithreading module that allows the management of multiple threads. However, it usually causes greater energy wastage. To improve multithreading in sensor networks, a Multithreading Model for an Efficient Data Delivery (MMEDD) using protothreads is proposed in this paper. Intensive experiments have been conducted on COOJA simulator that is integrated in Contiki. The results show that  MMEDD provides better ratio message reception rate/energy consumption than other architectures

Distributed Fault-Tolerant Algorithm for Wireless Sensor Networks

Wireless Sensor Networks (WSNs) are a set of tiny autonomous and interconnected devices. These nodes are scattered in a region of interest to collect information about the surrounding environment depending on the intended application. In many applications, the network is deployed in harsh environments such as battlefield where the nodes are susceptible to damage. In addition, nodes may fail due to energy depletion and breakdown in the onboard electronics. The failure of nodes may leave some areas uncovered and degrade the fidelity of the collected data. Therefore, establish a fault-tolerant mechanism is very crucial. Given the resource-constrained setup, this mechanism should impose the least overhead and performance impact. This paper focuses on recovery process after a fault detection phase in WSNs. We present an algorithm to recover faulty node called Distributed Fault-Tolerant Algorithm (DFTA).The performance evaluation is tested through simulation to evaluate some factors such as: Packet delivery ratio, control overhead, memory overhead and fault recovery delay. We compared our results with referenced algorithm: Fault Detection in Wireless Sensor Networks (FDWSN), and found that our DFTA performance outperforms that of FDWSN

Effet des touffes de Guiera senegalensis (J.F. Gmel) sur la fertilité des sols dans la région de maradi (Niger)

Objectifs : A Guidan Bakoye, dans la région de Maradi au Niger, pour faire face à la dégradation et la baisse de la fertilité des terres, les paysans ont entre autres adopté la régénération naturelle assistée des espèces ligneuses telles que Guiera  (Guiera du Sénégal). Cette étude traite de l’influence des touffes de cet arbuste sur la fertilité des sols dans le terroir de Guidan Bakoye.Méthodologies et résultats : Un dispositif en blocs randomisés complet avec trois répétitions des touffes, a été utilisé en plein champ. Des prélèvements des sols ont été effectués autour des touffes selon les points cardinaux, les distances 0, 50, 100, 150 et 200 cm de la touffe et la profondeur du sol (0 -10 ; 10 -20, 20 - 30 et 30 -40 cm), et leurs caractéristiques physico-chimiques ont été déterminées. Les résultats obtenus ont révélé généralement une amélioration significative des paramètres physico-chimiques des sols localisés à proximité des touffes de Guiera senegalensis.Conclusion et application de la recherche : Il ressort de cette étude, un fort taux de repeuplement de Guiera senegalensis (1800 pieds/ha) dans le terroir grâce à la régénération naturelle assistée et à l’introduction de la technique de marcottage. Par ailleurs, les résultats des analyses physico-chimiques des sols sous Guiera senegalensis, ont montré l’absence de changement textural avec la distance, et la prédominance des sables dans les horizons de surface indiquant que les touffes de Guiera senegalensis piègent essentiellement les sables transportés par les vents. Il est aussi apparu que les touffes de Guiera senegalensis ne semblent pas influencer le pH, la capacité d’échanges cationiques et le Ca contrairement à la matière organique, au phosphore, Mg et K. En définitive, les touffes de Guiera senegalensis améliorent moyennement les propriétés physico-chimiques du sol.Mots clés : Touffes, Guiera senegalensis, paramètres physico-chimiques des sols, Guidan Bakoye, MaradiEffect of Guiera senegalensis (JF Gmel) tufts on soil fertility in Maradi (Niger)ABSTRACTObjectives: In arid and semi-arid, the degradation and the decline in the fertility of land is a major concern for farmers. At Guidan Bakoye, in the Maradi region, to cope with this, the farmers have adopted the assisted natural regeneration to rebuild a degraded environment due to uncontrolled use. Thus, woody species like Guiera senegalensis (Guiera du Sénégal) have been bred and maintained in this region. The present study deals with the influence of the tufts of this plant on the soil fertility of Guidan Bakoye.Methodology and Results: A device block randomized complete with three repetitions of the tufts, was used in the field. Soil Samples were carried out around the tufts according to the cardinal points, the distances of 0, 50, 100, 150 and 200 cm of the tuft and the soil depth (0 -10 ; 10 -20, 20 -30 and 30 -40 cm).Conclusion and application of research: This study show a high rate of Guiera senegalensis repopulation (1800 plants/ha) in the soil through assisted natural regeneration and the introduction of the technique of layering. In addition, the results of the physico-chemical analysis of soils under Guiera senegalensis have shown the absence of textural change with the distance, and the predominance of sand in the surface horizons, indicating that the tufts of Guiera senegalensis trap essentially the sand transported by the wind. It is also apparent that the tufts of Guiera senegalensis did not seem to influence the pH, the capacity of the cation exchange and the Ca in contrast to the organic matter, phosphorus, Mg and K. In the end, the tufts of Guiera senegalensis improve moderately physico-chemical properties of the soil.Keywords : Tufts, Guiera senegalensis, physico-chemical parameters of the soil, Guidan Bakoye, Marad

WHISPER: A Location Privacy-Preserving Scheme Using Transmission Range Changing for Internet of Vehicles

Internet of Vehicles (IoV) has the potential to enhance road-safety with environment sensing features provided by embedded devices and sensors. This benignant feature also raises privacy issues as vehicles announce their fine-grained whereabouts mainly for safety requirements, adversaries can leverage this to track and identify users. Various privacy-preserving schemes have been designed and evaluated, for example, mix-zone, encryption, group forming, and silent-period-based techniques. However, they all suffer inherent limitations. In this paper, we review these limitations and propose WHISPER, a safety-aware location privacy-preserving scheme that adjusts the transmission range of vehicles in order to prevent continuous location monitoring. We detail the set of protocols used by WHISPER, then we compare it against other privacy-preserving schemes. The results show that WHISPER outperformed the other schemes by providing better location privacy levels while still fulfilling road-safety requirements

DSMAC: Privacy-Aware Decentralized Self-Management of Data Access Control Based on Blockchain for Health Data

In recent years, the interest in using wireless communication technologies and mobile devices in the healthcare environment has increased. However, despite increased attention to the security of electronic health records, patient privacy is still at risk for data breaches. Thus, it is quite a challenge to involve an access control system especially if the patient’s medical data are accessible by users who have diverse privileges in different situations. Blockchain is a new technology that can be adopted for decentralized access control management issues. Nevertheless, different scalability, security, and privacy challenges affect this technology. To address these issues, we suggest a novel Decentralized Self-Management of data Access Control (DSMAC) system using a blockchain-based Self-Sovereign Identity (SSI) model for privacy-preserving medical data, empowering patients with mechanisms to preserve control over their personal information and allowing them to self-grant access rights to their medical data. DSMAC leverages smart contracts to conduct Role-based Access Control policies and adopts the implementation of decentralized identifiers and verifiable credentials to describe advanced access control techniques for emergency cases. Finally, by evaluating performance and comparing analyses with other schemes, DSMAC can satisfy the privacy requirements of medical systems in terms of privacy, scalability, and sustainability, and offers a new approach for emergency cases

Effet des touffes de Hyphaene thebaica (Mart) sur la production du mil dans la région de Maradi (Niger)

La région de Maradi est confrontée à la saturation de l’espace et à la baisse généralisée de la fertilité des sols. Pour faire face à cette situation, les paysans ont adopté l’association céréales – légumineuses, l’apport des fertilisants par micro doses et l’utilisation des ligneux dans les champs. Ainsi, dans le terroir de El Guéza, les céréales sont cultivées en association avec l’arbuste Hyphaene thebaica, très répandu dans la localité. C’est dans cette optique que cette étude a été conduite pour évaluer l’influence des touffes de Hyphaene thebaica sur la production du mil dans ce terroir. Ainsi, des essais de culture du mil ont été menés selon un dispositif en blocs randomisés complet sur 3 parcelles avec touffes de Hyphaene thebaica et une parcelle témoin (sans touffes). Les résultats obtenus ont révélé qu’autour de la touffe de Hyphaene thebaica, le mil présente un enracinement très dense et bien développé alors qu’hors Hyphaene thebaica, il a des racines fines, moins denses et développées latéralement. Par ailleurs, les rendements en grains et en paille autour de Hyphaene thebaica sont respectivement de 1300 à 1820 kg/ha et 4630 à 6740 kg/ha alors qu’ils sont de 440 kg/ha et 2000 kg/ha pour le témoin. Cette étude montre clairement que les touffes de Hyphaene thebaica améliorent la production du mil.© 2015 International Formulae Group. All rights reserved.Mots clés: Touffes, Hyphaene thebaica, mil, rendements, El Guéza, MaradiEnglish Title:  Effect of Hyphaene thebaica (Mart) tufts on the millet production in Maradi region (Niger)English AbstractThe region Maradi is facing the land saturation and the general decline of soil fertility. To cope, farmers have adopted several techniques like “association cereals – legumes”, input of micro-doses fertilizers and the use of woody species in the fields. Thus, in the land of El Guéza, cereal crops grains are grown in combination with Hyphaene thebaica shrub, widespread in this locality. It is in this light that this study was conducted to evaluate the influence of Hyphaene thebaica tufts on millet production in this region. Thus, millet cultivation trials were conducted according to a randomized complete block design of 3 plots with Hyphaene thebaica tufts and a control plot (without tufts). The results obtained revealed that around the tufts of Hyphaene thebaica, millet has a very dense root and well developed whereas outside Hyphaene thebaica, millet has fine roots, less denses and developed laterally. Moreover, the yields of grain and straw around Hyphaene thebaica are 1300-1820 kg / ha from 4630 to 6740 kg / ha while they are 440 kg / ha and 2,000 kg / ha for the control respectively. This study clearly shows that the tufts of Hyphaene thebaica improve millet production.© 2015 International Formulae Group. All rights reserved.Keywords: Tufts, Hyphaene thebaica, millet, yields, El Guéza, Marad

Intégration des Solutions Bio-inspirées pour une Gestion optimale dans les Réseaux de Capteur sans Fils

During the past few years, wireless sensor networks witnessed an increased interest in both the industrial and the scientific community due to the potential wide area of applications. However, sensors’ components are designed with extreme resource constraints, especially the power supply limitation. It is therefore necessary to design low power, scalable and energy efficient protocols in order to extend the lifetime of such networks. Cluster-based sensor networks are the most popular approach for optimizing the energy consumption of sensor nodes, in order to strongly influence the overall performance of the network. In addition, routing involves non negligible operations that considerably affect the network lifetime and the throughput. In this thesis, we addressed the clustering and routing problems by hiring intelligent optimization methods through biologically inspired computing, which provides the most powerful models that enabled a global intelligence through local and simple behaviors. We proposed a distributed clustering approach based on the nest-sites selection process of a honeybee swarm. We formulated the distributed clustering problem as a social decision-making process in which sensors act in a collective manner to choose their cluster heads. To achieve this choice, we proposed a multi- objective cost-based fitness function. In the design of our proposed algorithm, we focused on the distribution of load balancing among each cluster member in order to extend network lifetime by making a tradeoff between the energy consumption and the quality of the communication link among sensors. Then, we proposed a centralized cluster-based routing protocol for wireless sensor networks by using the fast and efficient searching features of the artificial bee colony algorithm. We formulated the clustering as a linear programming problem and the routing problem is solved by proposing a cost-based function. We designed a multi-objective fitness function that uses the weighted sum approach, in the assignment of sensors to a cluster. The clustering algorithm allows the efficient building of clusters by making a tradeoff between the energy consumption and the quality of the communication link within clusters while the routing is realized in a distributed manner. The proposed protocols have been intensively experimented with a number of topologies in various network scenarios and the results are compared with the well-known cluster-based routing protocols. The results demonstrated the effectiveness of the proposed protocols.Au cours de ces dernières années, les réseaux de capteurs sans fils ont connu un intérêt croissant à la fois au sein de la communauté scientifique et industrielle en raison du large potentiel en terme d’applications offertes. Toutefois, les capteurs sont conçus avec d’extrêmes contraintes en ressources, en particulier la limitation de l’énergie. Il est donc nécessaire de concevoir des protocoles efficaces, évolutifs et moins consommateur d’énergie afin de prolonger la durée de vie de ces réseaux. Le clustering est une approche très populaire, utilisée pour l’optimisation de la consommation d’énergie des capteurs. Cette technique permet d’influencer fortement la performance globale du réseau. En outre, dans de tels réseaux, le routage génère un nombre assez élevé d’opérations non négligeables qui affectent considérablement la durée de vie du réseau ainsi que le débit offert. Dans cette thèse, nous nous sommes intéressés d’une part aux problèmes de clustering et de routage en utilisant des méthodes d’optimisation inspirées de certaines sociétés biologiques fournissant des modèles puissants qui conduisent à l’établissement d’une intelligence globale en se basant sur des comportements individuels très simples. Nous avons proposé une approche de clustering distribuée basée sur le processus de sélection des sites de nidification chez les colonies d’abeilles. Nous avons formulé le problème de clustering distribuée comme un processus social de prise de décision dans lequel les capteurs agissent d’une manière collective pour choisir des représentants au sein de leurs clusters respectifs. Le protocole proposé assure une distribution de l’équilibrage de charge entre les membres de chaque cluster afin de prolonger la durée de vie du réseau en faisant un compromis entre la consommation d’énergie et la qualité du canal de communication. D’autre part, nous avons proposé un protocole de routage basé sur des clusters en utilisant un algorithme inspiré du phénomène de butinage des abeilles. Nous avons formulé le problème de clustring comme un problème de programmation linéaire alors que le problème du routage est résolu par une fonction de coûts. L’algorithme de clustering permet la construction efficace des clusters en faisant un compromis entre la consommation d’énergie et la qualité du canal communication au sein des clusters tandis que le routage est réalisé de manière distribuée. Les protocoles proposés ont été intensivement expérimentés sur plusieurs topologies dans différents scénarios de réseaux et comparés avec des protocoles bien connus de clustering et routage. Les résultats obtenus démontrent l’efficacité des protocoles proposés

Virtual Machines Performance in HPC Environments

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