Wireless Sensor Networks are often deployed in unattended environments and thus an adversary could inject misleading information in the network and even fool other nodes, making them believe it is an authentic device. Different approaches in the literature have addressed this problem while taking into account the performance requirements of sensors (QoS, Memory, CPU). The most promising approaches are based on key disclosure. However, these approaches introduce delay in authentication and are thus susceptible to denial-of-service (DoS) attacks. In addition, delayed key disclosure schemes do not minimize the energy consumption overhead. In this paper, we propose an efficient authentication mechanism which integrates a Bloom Filter in order to authenticate sensors. We demonstrate that the use of multiple MACs in delayed key disclosure schemes, with the integration of Bloom filter, mitigates the risk of DoS attacks. We assess the feasibility of our protocol with a set of scenarios. Our results confirm that our authentication protocol is reducing the false positive rate of a Bloom Filter.

Due to the limited capacity of road networks and sporadic on-route events, road traffic congestions are posing serious problems in most big cities worldwide and resulting in considerable number of casualties and financial losses. In order to deal efficiently with these problems and alleviate their impact on individuals, environment, and economic activities, advanced traffic monitoring and control tools (e.g., SCATS and SCOOT) are being widely used in hundreds of major cities in the world. However, due to increasing road traffic and dynamic spatio-temporal events, additional proactive mechanisms remain needed to prevent traffic congestions. Within this context, we argue that the emergent V2X communication technologies, and especially V2I (Vehicle to Infrastructure), would be of great help. To this end, we investigate in this paper the opportunities that could be offered by V2I technology in improving commuters' journey duration and mitigating the above irritating and frequent problems. We then propose an approach where road-side facilities (e.g. traffic light controllers at road intersections) communicate traffic light cycle information to approaching vehicles. Based on this information, the vehicles collaboratively determine their optimal speeds and other appropriate actions to undertake in order to cross road intersections with minimum delays while ultimately avoiding stoppings. The obtained evaluation results show that our approach achieves a significant gain in terms of the commuters' average travel time reduction.

Many security protocols have been developed to handle security problems in various circumstances. However, these protocols are often limited to client/server architectures and cannot answer special application and network's needs such as securing audio/video applications or transactions between several nodes in wireless mesh networks. In this paper, we propose extending the Transport Layer Security (TLS) protocol to securely exchange data between multiple nodes through a single TLS session and to provide third-party auditing capability. We propose a formal validation of our extension with the EVA language using Hermes.

The web is one of the most important mean of disseminating maps to users worldwide. These maps are commonly generated, on-the-fly, by extracting and displaying pre-processed data which is stored beforehand in specific databases. Though rapid, this approach lacks flexibility and does not necessarily provide the user with all the relevant spatial data at the right time and in the right way. Indeed, it may burden the user's screen with useless data while marginalizing some objects or landmarks which are explicitly requested by the user. In order to provide the user with personalized web map services, we propose to progressively generate, transmit, and display spatial objects according to the decreasing order of their importance for the user. The approach is based upon the use of software agents which compete for the occupation of the limited space of the user' screen. As illustration, we apply our approach to the context of on-the-fly tourist web mapping scenario.

The overall progresses in wireless sensor networks are making the assumption that all the sensor nodes participate in the provision of one single service. However, there is a growing need for accommodating multiple services simultaneously within the same network. In spite of the existence of some relevant attempts, long-term work for binding multiple services on the same sensor network remain necessary. The issue of controlling the admission of concurrent tasks at the sensor level is the cornerstone of this work. In this paper, we propose a service admission control (SAC) approach that allows any sensor node to decide about the admission or denial of new sensing tasks. The admission strategy is based on the tasks already accepted, the new task frequency, and the sleep/wake period of the sensor node. The approach also gives hints on how to choose the frequency of the new tasks to increase the probability of being accepted. An investigation of the effect of the duration of wake time on the possible number of supported services is also presented.