Towards trusted volunteer grid environments

Intensive experiences show and confirm that grid environments can be considered as the most promising way to solve several kinds of problems relating either to cooperative work especially where involved collaborators are dispersed geographically or to some very greedy applications which require enough power of computing or/and storage. Such environments can be classified into two categories; first, dedicated grids where the federated computers are solely devoted to a specific work through its end. Second, Volunteer grids where federated computers are not completely devoted to a specific work but instead they can be randomly and intermittently used, at the same time, for any other purpose or they can be connected or disconnected at will by their owners without any prior notification. Each category of grids includes surely several advantages and disadvantages; nevertheless, we think that volunteer grids are very promising and more convenient especially to build a general multipurpose distributed scalable environment. Unfortunately, the big challenge of such environments is, however, security and trust. Indeed, owing to the fact that every federated computer in such an environment can randomly be used at the same time by several users or can be disconnected suddenly, several security problems will automatically arise. In this paper, we propose a novel solution based on identity federation, agent technology and the dynamic enforcement of access control policies that lead to the design and implementation of trusted volunteer grid environments.Comment: 9 Pages, IJCNC Journal 201

Challenges and trends in wireless ubiquitous computing systems

In the last decade, the Internet paradigm has been evolving toward a new frontier with the emergence of ubiquitous and pervasive systems, including wireless sensor networks, ad hoc networks, RFID systems, and wireless embedded systems. In fact, while the initial purpose of the Internet was to interconnect computers to share digital data at large scale, the current tendency is to enable ubiquitous and pervasive computing to control everything anytime and at a large scale. This new paradigm has given rise to a new generation of networked systems, commonly known as Internet-of-Things or Cyber-Physical Systems

A trust-based architecture for managing certificates in vehicular ad hoc networks

International audienceIn this paper, we propose a secure and distributed public key infrastructure for VANETs. It is based on an hybrid trust model which is used to determine the trust metric (Tm) of vehicles. It consists on a monitoring system processing on two aspects: the cooperation of vehicles and the legitimacy of the broadcasted data. We propose a fuzzy-based solution in order to decide about the honesty of vehicles. Then, the vehicles which are trusted (Tm = 1), also, they have at least one trusted neighbor can candidate to serve as certification authorities CAs in their clusters. In order to increase the stability of our distributed architecture, the CA candidate which has the lowest relative mobility will be elected as certification authority CA. A set of simulations is conducted. We evaluate particularly the efficiency and the stability of the clustering algorithm as a function of the speed, the average number of vehicles on the platoon and the percentage of trusted vehicles

PKI and UDDI based trust centre: an attempt to improve web service security

4 pagesInternational audienceNowadays Internet becomes the most used tool for the ever increasing amount of various transactions between institutions, organizations and more generally between clients and providers. Conducted studies and experiments showed that it is more convenient to provide and achieve these transactions as web services (WS) to guarantee their flexibility and their reuse. So far these services and the corresponding providers' URLs are advertised on specific UDDIs (Universal Description, Discovery and Integration). As such, after finding the requested service any given client contacts the right provider to negotiate the service access procedure. These first contacts between clients and providers are usually and ommonly not protected (Encrypted) yielding enough room for Hackers to intrude into these unprotected messages. In this paper, we propose a securing approach based on both the PKI nfrastructure and some proposed improvements of the UDDI functioning in an attempt to provide adequate security for web service

Technology Integration Framework for Fast and Low Cost Handovers—Case Study: WiFi-WiMAX Network

The Next Generation Wireless Networks (NGWNs) are seemed to be heterogeneous networks based on the integration of several wireless technologies. These networks are required to achieve performances equivalent to classic wireless networks by ensuring the continuity of communications and the homogeneity of network management during horizontal and vertical handovers. This task is even more important when management services, like security and quality of service (QoS), are deployed at access technology level. In this paper, we propose a framework for heterogeneous wireless technology integration based on network architecture skeleton and a handover management mechanism. This framework optimizes the layer-2 handover procedure to achieve performances required by sensitive applications while ensuring the minimization of signaling overhead required for operated networks. As an application example, we make use of this framework to propose a heterogeneous network based on WiFi and WiMAX technologies. We present an application example of the framework using the specification of a WiFi-WiMAX network. We propose several performance evaluations based on simulation tests based on this application. The latter confirm the efficiency of handover delay optimization and the minimization of management signaling costs

A Node Quality based Clustering Algorithm in Wireless Mobile Ad Hoc Networks

AbstractA new strategy for clustering a wireless AD HOC network is proposed. The main contribution of our work is to improve Weighted Clustering Algorithm (WCA) [5] and other similar algorithms. In literature, the node degree is considered as an important weight metric in clusterhead selection process. Unfortunately, this metric is not consistent especially when it is considered separately at the node environment such as the neighbours’ location within the transmission range zone of this node. To overcome this inefficiency, we propose two new models. Thereafter, we combined these two models to take profit of their efficiencies. The new combined model, motivates us to generate and reformulate many node degree based formula given in literature and dealing with Quality of Clustering (QoS) as stability and load balancing clustering parameters. We showed that our algorithm outperforms WCA in the in terms of cluster formation and stability

The Impact of Nonlinear Mobility Models on Straight Line Conflict Detection Algorithm for UAVs

Conflict detection is an essential issue in flying ad hoc networks (FANETs) to ensure the safety of unmanned aerial vehicles (UAVs) during flights. This paper assesses the applicability and utilization of a conflict detection algorithm that sees immediate trajectory as a straight line for short periods with nonlinear mobility models such as Gauss–Markov (GM). First, we use a straight line conflict detection algorithm with two nonlinear mobility models. Then, we perform an extensive simulation study to evaluate the performance. Additionally, we present a comprehensive discussion to tune the collision detection parameters efficiently. Simulation results indicate that an algorithm considering the immediate trajectory as a straight line to predict conflicts between UAVs can be applied with nonlinear mobilities and can provide an acceptable performance measured in false and missed alarms