BANZKP: a Secure Authentication Scheme Using Zero Knowledge Proof for WBANs

-Wireless body area network(WBAN) has shown great potential in improving healthcare quality not only for patients but also for medical staff. However, security and privacy are still an important issue in WBANs especially in multi-hop architectures. In this paper, we propose and present the design and the evaluation of a secure lightweight and energy efficient authentication scheme BANZKP based on an efficient cryptographic protocol, Zero Knowledge Proof (ZKP) and a commitment scheme. ZKP is used to confirm the identify of the sensor nodes, with small computational requirement, which is favorable for body sensors given their limited resources, while the commitment scheme is used to deal with replay attacks and hence the injection attacks by committing a message and revealing the key later. Our scheme reduces the memory requirement by 56.13 % compared to TinyZKP [13], the comparable alternative so far for Body Area Networks, and uses 10 % less energy

Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

Capteurs multimédias collaboratifs pour une ville connectée et intelligente

Due to their high application potential in various innovative fields (telemonitoring, telemedicine, etc.), Wireless Multimedia Sensor Networks (WMSN) arouse the interest of numerous research projects. In addition to inherent constraints of scalar sensor networks in terms of energy limitation, deployment, coverage, reliability, ..., WMSNs impose new constraints related to the captured data. Indeed, multimedia data are very voluminous in comparison to scalar data and, in addition, have a time constraint (real-time delivery). Moreover, their semantic content, very rich, is subject to different perceptions and interpretations depending on the quality of the acquisition. As a target application, this dissertation focuses detecting available car parking spaces within a large city or a metropolis. Nevertheless, the proposed approaches can be used for a wide variety of WMSN applications for surveillance purposes.In this context, the main objective remains the network lifetime maximization while ensuring an acceptable perceived quality at the destination station. The studied approaches are of a distributed nature for scalability reasons, required in WMSN. Two main axes have been targeted: data processing at source nodes and data routing toward the destination.In the data processing axis, the main problem lies in the quality of the data to be transmitted. In general, the higher the quality is, the larger the data are, and consequently more important is the energy consumption and vice versa. It is therefore a question of finding a balance that preserve the energy resources; i.e. maximize the network lifetime while ensuring an acceptable quality of the sent data. The latter is the result of an encoding process at the source level.Thus, we proposed a fully distributed algorithm that maximizes the network lifetime by optimally balancing the encoding power and the source rate at the source node in order to meet a desired visual quality at the destination station. In opposition to existing approaches, our algorithm, of distributed nature, is ensured to find such a trade-off whatever the initial network configuration is.As a second step, we focuses on data routing. In fact, due to the complexity of this problem, especially in a decentralized context, literature works have not considered jointly data processing and routing. In other words, routing was considered as a network input.In the research work of this thesis, we have subsequently shown that the routing directly impacts the results of the network lifetime maximization process. Indeed, we have analyzed the behavior of several routing protocols in WMSN and the obtained results highlighted this influence. We have therefore proposed an analytic model integrating simultaneously the encoding of data at the source nodes and their routing to the base station. We have developed a semi-distributed resolution of this problem. The results obtained were very encouraging.Thus, in the second part, a fully distributed solution was proposed, in which, the routing axis cannot be achieved without the parameters, that should be determined and updated by the data processing axis. On the other hand, the data processing axis cannot be achieved without the routing tables updated by the routing axis. The proposed solution allows: a) an end-to-end routing with local decisions at each video sensor node and b) the choose of the sufficient number of paths needed to ensure a reliable data transmission.For the rest, we have completed our work by considering more realistic constraints, in particular the dynamic reliability of the links as well as the variation of their capacities (according to the remaining energy of the intermediate nodes). The simulation results showed savings of around 25% of the total energy.En raison de leur fort potentiel applicatif dans différents domaines innovants (télésurveillance, télémédecine, etc.), les réseaux de capteurs multimédias sans fil (RCMSF) suscitent l’intérêt de nombreux travaux de recherche. En outre des contraintes soulevées par les réseaux de capteurs scalaires, les RCMSF imposent de nouvelles contraintes liées à la nature même des données capturées et manipulées. En effet, les données multimédias sont, sans aucune mesure, très largement volumineuses en comparaison aux données scalaires. De plus, leur contenu sémantique, très riche, dépendent de la qualité de l’acquisition. Dans le cadre de cette thèse, nous nous sommes intéressés à la problématique pratique d’un réseau de capteurs multimédias permettant de renseigner les automobilistes en temps réel sur les places de parking disponibles au niveau d’une ville, voire d’une agglomération. Cependant, de manière générale, les approches proposées dans nos travaux concernent tout RCMSF de surveillance.Dans ce contexte, l’objectif principal reste de maximiser la durée de vie du réseau tout en assurant une qualité perçue acceptable au niveau de la destination et ce sous un contrôle distribué (pour des raisons de passage à l’échelle évidentes). Deux axes sont à considérer : le traitement des données à la source et leur routage.Dans l'axe traitement de données, le problème principal réside dans la « qualité » des données à transmettre. De manière générale, plus la qualité est importante, plus les données sont volumineuses et conséquemment la consommation énergétique est importante et vice-versa. Il s’agit donc de trouver un équilibre qui préserve les ressources énergétiques, c-à-d. maximiser sa durée de vie tout en assurant une qualité acceptable des données envoyées. Cette dernière est le résultat d’un processus d’encodage au niveau de la source.Ainsi, nous avons d'abord abordé l'axe de traitement de données et proposé un algorithme complètement distribué qui maximise la durée de vie du réseau tout en assurant de manière optimale un équilibre entre la puissance d'encodage au niveau de la source et la qualité vidéo exigée au niveau de la destination. Contrairement aux approches existantes, notre algorithme, de nature distribuée, est assuré de trouver un tel compromis quelle que soit la configuration initiale du réseau.En raison de la complexité de ce problème, notamment dans un contexte décentralisé, les travaux antérieurs n’ont traité que la partie traitement de données indépendamment du routage. En d’autres termes, le routage a été considéré comme une entrée.Dans les travaux de recherche de cette thèse, nous avons par la suite montré que le routage impacte directement les résultats du processus de prolongation de la durée de vie du réseau. En effet, nous avons analysé le comportement de plusieurs protocoles de routage dans les RCMSF et les résultats obtenus ont mis en exergue cette influence. Nous avons donc proposé un modèle analytique intégrant de facto et le codage des données au niveau des sources et leur routage jusqu’à la station de traitement. Nous avons développé une résolution semi-distribuée de ce problème. Les résultats obtenus étaient très encourageants.Ainsi, dans la deuxième partie, une solution entièrement distribuée a été proposée, dans laquelle, l'axe de routage ne peut pas être réalisé sans les paramètres déterminés et mis à jour par l'axe de traitement de données, et inversement. La solution proposée permet: a) un routage de bout en bout avec des décisions locales dans chaque nœud capteur et b) de déterminer le nombre suffisant de chemins nécessaires pour assurer une transmission fiable de données.Pour la suite, nous avons complété nos travaux en considérant plus de contraintes réalistes, notamment la fiabilité des liens ainsi que la variation de leurs capacités (en fonction de l'énergie restante des nœuds intermédiaire). Les résultats de simulation ont montré une économie d’environs 25% de l'énergie totale

Closed Peripheral Coverage in Wireless Multimedia Sensor Networks

International audienceBecause of the visual nature (images and videos) of the captured data, the coverage problem in Wireless Multimedia Sensor Networks (WMSNs) is totally different from traditional scalar sensor networks and can be defined in several ways according to the target application. In this paper, we focus on one particular coverage, we called Closed Peripheral Coverage (CPC). This type of coverage is present in several realistic applications as military camp surveillance, very sensitive buildings (i.e., nuclear center) surveillance, contaminated region monitoring, etc. The objective hence is to detect any intrusion coming from the outside (viewed by at least one multimedia sensor node). To the best of our knowledge, this is the first research work addressing this issue. Briefly, CPC problem can be defined as follow: after a random deployment of multimedia sensor nodes around the region of interest (i.e., Building to monitor), the goal is to schedule several sets of nodes (i.e., cover sets) such that each of which forms a closed "ring" around the region of interest. Hence, instead activating all nodes at once, the cover sets are scheduled to be activated serially, which ensures a significant network lifetime prolongation improvement. In this paper, we study the CPC problem and present two variants of a centralized algorithm. The preliminary simulation results show clearly the effectiveness of the proposed approaches by a factor varied from 2 to 8 in comparison to the basic approach

Allocation Optimale des Ressources pour la Maximisation de la Durée de Vie des Réseaux de Capteurs Multimédias Sans Fil

International audienceDe nos jours, les caméras sans fil sont largement déployées dans divers domaines d'application tels que les domaines commerciaux et militaires. Cependant, dans un tel réseau, les données capturées sont généralement volumineuses et nécessitent un traitement local, entraˆınantentraˆınant ainsi un besoinénergétiquébesoin´besoinénergétiqué elevé. Par conséquent, leprobì eme le plus important consistè a trouver unéquilibreun´unéquilibre entre le niveau de compression de la vidéo au niveau de la source et la qualité de cettedernì ere exigée par l'utilisateur final, tout en maximisant la durée de vie du réseau. ` A cette fin, nous proposons un algorithme distribué qui considère leprobì eme d'allocation des ressources dans un réseau de capteurs vidéo sans fil. Par opposition aux approches existantes, notre algorithme, est fourni pour trouver un tel compromis quelle que soit la configuration initiale du réseau. Outre, leprobì eme d'optimisation formulé prend en considération le changement dynamique des capacités des liens

Joint Routing/Encoding-Power for Network Lifetime Maximization in WVSN

International audienceOne of the most important issues, in Wireless video sensor networks (WVSNs), is to achieve an optimal video data encoding through an efficient resource allocation, while maximizing the overall network lifetime. However, the multimedia data is usually voluminous and delivering the compressed video data to the forwarding node poses an emergent demand, to simultaneously optimizing the video encoding and data routing performance in order to maximize the network lifetime. Based on unknown routing matrix, in this paper, we focus on the integration of routing into the analytic model proposed in our previous work. The simulation results show that our proposed solution consumes less than 0.03% of the total battery and ensures a prolongation of the network lifetime compared to the literature approaches

Optimal power/rate trade-off for internet of multimedia things lifetime maximization under dynamic links capacity

International audienceToday, wireless cameras are widely deployed in various applications such as in commercial and military domains (eg. patients monitored in smart hospitals, multimedia surveillance deployed in smart cities, intelligent multimedia monitoring of an ecological system, etc.). The design of such systems can be achieved by allowing the interaction between all their component objects (i.e., internet of things), which is one of the preoccupations of the researchers this last decade. However, using the multimedia sensor nodes for the internet of things (IoT) is problematic in term of power consumption, since these latter would be wireless and battery powered. Within the wider context of IoT, Wireless Multimedia Sensor Networks (WMSNs) can be a promising technology for the aforementioned domains. However, in a such network, the captured data is usually voluminous and requires local processing, and thus, entailing a higher energy requirement. Therefore, the most important issue is to balance the video data coding versus the perceived video quality at the sink, while maximizing the overall network lifetime. To this end, we propose a fully distributed algorithm, that considers the problem of allocating the resources in wireless video sensor network, in a way to ensure a trade-off between both: the encoding power and the source rate at each node, while serving the desired video quality requirement. In opposition to existing approaches, our algorithm, of distributed nature, is provided to find such a trade-off whatever the initial network configuration is. In addition, a dynamic change of links capacity is considered with the limited transmission and reception powers. A new problem is then formulated to cope with the channel transmission error and it is solved

Maximum network lifetime with optimal power/rate and routing trade-off for Wireless Multimedia Sensor Networks

International audienceWireless Multimedia Sensor Networks (WMSN) are today considered as a promising technology, notably because of the availability of miniaturized multimedia hardware (e.g., CMOS cameras). Nevertheless, they do raise new research challenges; i.e., multimedia content is much more voluminous and rich in comparison to scalar one. Hence, multimedia data need pre-processing, namely coding, before they are delivered to the sink. In WMSN, meeting the required visual quality at the sink whilst taking into account the intrinsic network limitations, energy in particular, remains very challenging. In fact, higher visual quality of the data increases its volume, which in turn consumes more network resources and vice versa. The problem is more complex when including the data routing, especially when the routing is initially unknown. In this paper, we focus on the problem of simultaneously optimizing the video encoding at the source nodes and the routing of the generated data (i.e., the routing matrix is initially unknown) to the sink in order to maximize the network lifetime. This issue is tackled through the proposition of an analytic model. Based on the latter, two solutions have been studied. In the first one, of a static nature (i.e., network topology is static), the routes are calculated using the shortest path routing protocol toward the sink. The evaluation we made has shown that our proposed solution consumes less than 0.030% of the total battery while it increases the whole network lifetime nearly between 7 and 12 times, depending on the considered topologies, in comparison to the baseline approach (i.e., without optimization). Afterwards, in order to handle dynamic topology changes and to consider the link reliability, the work have been extended to the selection of routing paths, in a fully distributed fashion (i.e., using a local decision hop-by-hop routing protocol) with respect to both the shortest ones and their reliability. The second solution was evaluated through two different dynamic topologies. The simulation results show an energy consumption inferior to 0.025% and 0.080% of the total battery in the first and the second topology, respectively, with an improvement of the network lifetime that is multiplied by around 7 in comparison to the baseline approach

Routing impact on Network Lifetime Maximization using Power/Rate trade-off in WVSN

International audienceIn Wireless multimedia sensor networks (WMSNs), one of the most important issues is to balance video data coding versus the perceived video quality at the sink, while maximizing the network lifetime. That is, better quality generates higher data rates and consequently consumes additional resources (i.e. energy). Finding such a balance is not obvious, especially in a distributed fashion. Previous research works have tackled this issue by not considering the routing issue; i.e. they consider that it has been done separately during the network initialization. In other term, routing is ”viewed” as a network input and not as a parameter to optimize. The purpose of this paper is to demonstrate, through extensive simulations, the impact of the routing policy on the approaches used to find such a balance. To this end, we first considered several well-known routing approaches in WMSNs and extensively analyzed the impact of each one by considering three main parameters: battery consumption, activity duration, and network lifetime. The simulation results show clearly the great impact of the considered routing approaches on the obtained resource’s consumption balance

Convergecast in Wireless Body Area Networks

International audienceWireless Body Area Networks (WBAN) is a recent challenging area in the domain of health monitoring. There are several concerns in this area ranging from energy efficient communication to designing delays efficient protocols that support nodes dynamicity induced by human body mobility. This paper focuses on the convergecast or data gathering protocols in WBAN. Our contribution is twofold. First, we extensively analyze the impact of postural body mobility on various classes of multi-hop convergecast strategies. Our study does not limit itself to the existing state-of-the-art in WBAN, we adapted to WBAN settings strategies from the areas of Delay Tolerant Networks (DTN) and Wireless Sensor Networks (WSN). We evaluate all these strategies via the OMNeT++ simulator that we enriched with realistic human body mobility models and channel models issued from the recent research on biomedical and health informatics. Our simulations show that existing results in DTN and WSN cannot be just extrapolated to WBAN without a deeper investigation. That is, existing convergecast strategies for DTN or WSN do not perform well with postural body movements because of the topological partitioning provoked by important link attenuations due to signal obstructions by clothes or body itself. Our extensive simulations give valuable insights and directions for designing efficient convergecast adaptive strategies in WBAN. Second, we propose and evaluate two novel classes of convergecast strategies. The first class integrates in the routing information the link attenuation while the second one exploits multi (pre-established) paths to the sink node. We stress all the strategies under a realistic channel model and present an extensive analysis in terms of resiliency to mobility, end-to-end delay and energy consumption for seven different mobility patterns. We advocate that, so far, there is no strategy for convergecast in WBAN that optimizes all the above criteria for all possible mobility patterns. However, each considered strategy can be a good candidate for a specific combination of parameters with a specific mobility pattern