Improving Performance of WSN Based On Hybrid Range Based Approach

Improving the performance of WSN supported hybrid range based approach. WSN is self-possessed minimization error of nodes prepared with limited resources, limited memory and computational abilities. WSNs reliably work in unidentified hubs and numerous situations, it's difficult to trade sensor hubs after deployment, and therefore a fundamental objective is to optimize the sensor nodes' lifetime. A WSN may be a set of a large number of resource-constrained sensor nodes which have abilities for information detection, processing, and short-range radio communication, Analysis localization error minimization based several applications of wireless sensor networks (WSN) need data regarding the geographical location of each detector node. Self-organization and localization capabilities are one in every of the foremost necessary needs in detector networks. It provides a summary of centralized distance-based algorithms for estimating the positions of nodes during very sensing nodes. Secure localization of unknown nodes during a very wireless detector network (WSN) may be a vital analysis subject wireless sensor networks (WSN), a component of enveloping computing, are presently getting used on a large scale to look at period environmental standing, Be that as it may, these sensors work underneath extraordinary vitality imperatives and are planned by remembering an application. Proposed approaches are sensing node location and challenging task, involve assessing sort of various parameters needed by the target application. In study realize drawback not sense positioning of nodes .but proposed approach formula recognizes the optimal location of nodes supported minimize error and best answer in WSN. Localization algorithms mentioned with their benefits and disadvantages. Lastly, a comparative study of localization algorithms supported the performance in WSN. This was often done primarily to offer a summary of the proposed approach known today for reliable data and minimizing the energy consumption in wireless sensor networks

Revisiting the Performance of the Modular Clock Algorithm for Distributed Blind Rendezvous in Cognitive Radio Networks

Abstract. We reexamine the modular clock algorithm for distributed blind rendezvous in cognitive radio networks. It proceeds in rounds. Each round consists of scanning twice a block of generated channels. The modular clock algorithm inspired the creation of the jump-stay ren-dezvous algorithm. It augments the modular clock with a stay-on-one-channel pattern. This enhancement guarantees rendezvous in one round. We make the observation that as the number of channels increases, the significance of the stay-on-one-channel pattern decreases. We revisit the performance analysis of the two-user symmetric case of the modular clock algorithm. We compare its performance with a random and the jump-stay rendezvous algorithms. Let m be the number of channels. Let p be the smallest prime number greater than m. The expected time-to-rendezvous of the random and jump-stay algorithms are m and p, respectively. Theis et al.’s analysis of the modular clock algorithm con-cludes a maximum expected time-to-rendezvous slightly larger than 2p time slots. Our analysis shows that the expected time-to-rendezvous of the modular clock algorithm is no more than 3p/4 time slots.

Multiple-polynomial LFSR based pseudorandom number generator for EPC Gen2 RFID tags

International audienceWe present a lightweight pseudorandom number generator (PRNG) design for EPC Gen2 RFID tags. It is based on a linear feedback shift register (LFSR) configured with multiple feedback polynomials that are selected by a physical source of randomness. The proposal successfully handles the inherent linearity of LFSR based PRNGs and satisfies the statistical requirements imposed by the EPC Gen2 standard. Statistical analysis of the sequences generated by our generator confirms the validity of the proposed technique.We show that our proposal has, moreover, a simpler hardware implementation and energy consumption than previous designs reported in the literature

Formal Verification of a Key Establishment Protocol for EPC Gen2 RFID Systems: Work in Progress

International audienceThe EPC Class-1 Generation-2 (Gen2 for short) is a standard Radio Frequency Identification (RFID) technology that has gained a prominent place on the retail industry. The Gen2 standard lacks, however, of verifiable security functionalities. Eavesdropping attacks can, for instance, affect the security of monitoring applications based on the Gen2 technology. We are working on a key establishment protocol that aims at addressing this problem. The protocol is applied at both the initial identification phase and those remainder operations that may require security, such as password protected operations. We specify the protocol using the High Level Protocol Specification Language (HLPSL). Then, we verify the secrecy property of the protocol using the AVISPA model checker tool. The results that we report show that the current version of the protocol guarantees sensitive data secrecy under the presence of a passive adversary

Secure Protocols for Key Pre-distribution, Network Discovery, and Aggregation in Wireless Sensor Networks

The term sensor network is used to refer to a broad class of networks where several small devices, called sensors, are deployed in order to gather data and report back to one or more base stations. Traditionally, sensors are assumed to be small, low-cost, battery-powered, wireless, computationally constrained, and memory constrained devices equipped with some sort of specialized sensing equipment. In many settings, these sensors must be resilient to individual node failure and malicious attacks by an adversary, despite their constrained nature. This thesis is concerned with security during all phases of a sensor network's lifetime: pre-deployment, deployment, operation, and maintenance. This is accomplished by pre-loading nodes with symmetric keys according to a new family of combinatorial key pre-distribution schemes to facilitate secure communication between nodes using minimal storage overhead, and without requiring expensive public-key operations. This key pre-distribution technique is then utilized to construct a secure network discovery protocol, which allows a node to correctly learn the local network topology, even in the presence of active malicious nodes. Finally, a family of secure aggregation protocols are presented that allow for data to be efficiently collected from the entire network at a much lower cost than collecting readings individually, even if an active adversary is present. The key pre-distribution schemes are built from a family of combinatorial designs that allow for a concise mathematical analysis of their performance, but unlike previous approaches, do not suffer from strict constraints on the network size or number of keys per node. The network discovery protocol is focused on providing nodes with an accurate view of the complete topology so that multiple node-disjoint paths can be established to a destination, even if an adversary is present at the time of deployment. This property allows for the use of many existing multi-path protocols that rely on the existence of such node-disjoint paths. The aggregation protocols are the first designed for simple linear networks, but generalize naturally to other classes of networks. Proofs of security are provided for all protocols

Trust assessment in 32 KiB of RAM : multi-application trust-based task offloading for resource-constrained IoT nodes

There is an increasing demand for Internet of Things (IoT) systems comprised of resource-constrained sensor and actuator nodes executing increasingly complex applications, possibly simultaneously. IoT devices will not be able to execute computationally expensive tasks and will require more powerful computing nodes, called edge nodes, for such execution, in a process called computation offloading. When multiple powerful nodes are available, a selection problem arises: which edge node should a task be submitted to? This problem is even more acute when the system is subjected to attacks, such as DoS, or network perturbations such as system overload. In this paper, we present a trust model-based system architecture for computation offloading, based on behavioural evidence. The system architecture provides confidentiality, authentication and non-repudiation of messages in required scenarios and will operate within the resource constraints of embedded IoT nodes. We demonstrate the viability of the architecture with an example deployment of Beta Reputation System trust model on real hardware

Threat Modelling Guided Trust-based Task Offloading for Resource-constrained Internet of Things

There is an increasing demand for Internet of Things (IoT) networks consisting of resource-constrained devices executing increasingly complex applications. Due to these resource-constraints, IoT devices will not be able to execute expensive tasks. One solution is to offload expensive tasks to resource-rich edge nodes. Which requires a framework that facilitates the selection of suitable edge nodes to perform task offloading. Therefore, in this paper, we present a novel trust model-driven system architecture, based on behavioural evidence, that is suitable for resource-constrained IoT devices that supports computation offloading. We demonstrate the viability of the proposed architecture with an example deployment of the Beta Reputation System trust model on real hardware to capture node behaviours. The open environment of edge-based IoT networks means that threats against edge nodes can lead to deviation from expected behaviour. Hence, we perform a threat modelling to identify such threats. The proposed system architecture includes threat handling mechanisms that provide security properties such as confidentiality, authentication and non-repudiation of messages in required scenarios and operate within the resource constraints. We evaluate the efficacy of the threat handling mechanisms and identify future work for the standards used

Sound based social networks

The sound environment is an eco of the activity and character of each place, often carrying additional information to that made available to the eyes (both new and redundant). It is, therefore, an intangible and volatile acoustic fingerprint of the place, or simply an acoustic snapshot of a single event. Such rich resource, full of meaning and subtleness, Schaeffer called Soundscape. The exploratory research project presented here addresses the Soundscape in the context of Mobile Online Social Networking, aiming at determining the extent of its applicability regarding the establishment and/or strengthening of new and existing social links. Such research goal demanded an interdisciplinary approach, which we have anchored in three main stems: Soundscapes, Mobile Sound and Social Networking. These three areas pave the scientific ground for this study and are introduced during the first part of the thesis. An extensive survey of the state-of-the-arte projects related with this research is also presented, gathering examples from different but adjacent areas such as mobile sensing, wearable computing, sonification, social media and contextaware computing. This survey validates that our approach is scientifically opportune and unique, at the same time. Furthermore, in order to assess the role of Soundscapes in the context of Social Networking, an experimental procedure has been implemented based on an Online Social Networking mobile application, enriched with environmental sensing mechanisms, able to capture and analyze the surrounding Soundscape and users' movements. Two main goals guided this prototypal research tool: collecting data regarding users' activity (both sonic and kinetic) and providing users with a real experience using a Sound-Based Social Network, in order to collect informed opinions about this unique type of Social Networking. The application – Hurly-Burly – senses the surrounding Soundscape and analyzes it using machine audition techniques, classifying it according to four categories: speech, music, environmental sounds and silence. Additionally, it determines the sound pressure level of the sensed Soundscape in dB(A)eq. This information is then broadcasted to the entire online social network of the user, allowing each element to visualize and audition a representation of the collected data. An individual record for each user is kept available in a webserver and can be accessed through an online application, displaying the continuous acoustic profile of each user along a timeline graph. The experimental procedure included three different test groups, forming each one a social network with a cluster coefficient equal to one. After the implementation and result analysis stages we concluded that Soundscapes can have a role in the Online Social Networking paradigm, specially when concerning mobile applications. Has been proven that current offthe- shelf mobile technology is a promising opportunity for accomplishing this kind of tasks (such as continuous monitoring, life logging and environment sensing) but battery limitations and multitasking's constraints are still the bottleneck, hindering the massification of successful applications. Additionally, online privacy is something that users are not enthusiastic in letting go: using captured sound instead of representations of the sound would abstain users from utilizing such applications. We also demonstrated that users who are more aware of the Soundscape concept are also more inclined to assume it as playing an important role in OSN. This means that more pedagogy towards the acoustic phenomenon is needed and this type of research gives a step further in that direction.O ambiente sonoro de um lugar é um eco da sua atividade e carácter, transportando, na maior parte da vezes, informação adicional àquela que é proporcionada à visão (quer seja redundante ou complementar). É, portanto, uma impressão digital acústica - tangível e volátil - do lugar a que pertence, ou simplesmente uma fotografia acústica de um evento pontual. A este opulento recurso, carregado de significados e subtilezas, Schafer chamou de Paisagem-Sonora. O projeto de investigação de carácter exploratório que aqui apresentamos visa o estudo da Paisagem-Sonora no contexto das Redes Sociais Móveis Em-Linha, procurando entender os moldes e limites da sua aplicação, tendo em vista o estabelecimento e/ou reforço de novos ou existente laços sociais, respectivamente. Para satisfazer este objectivo foi necessária uma abordagem multidisciplinar, ancorada em três pilares principais: a Paisagem-Sonora, o Som Móvel e as Redes Sociais. Estas três áreas determinaram a moldura científica de referência em que se enquadrou esta investigação, sendo explanadas na primeira parte da tese. Um extenso levantamento do estado-da-arte referente a projetos relacionados com este estudo é também apresentado, compilando exemplos de áreas distintas mas adjacentes, tais como: Computação Sensorial Móvel, Computação Vestível, Sonificação, Média Social e Computação Contexto-Dependente. Este levantamento veio confirmar quer a originalidade quer a pertinência científica do projeto apresentado. Posteriormente, a fim de avaliar o papel da Paisagem-Sonora no contexto das Redes Sociais, foi posto em prática um procedimento experimental baseado numa Rede Social Sonora Em-Linha, desenvolvida de raiz para dispositivos móveis e acrescida de mecanismos sensoriais para estímulos ambientais, capazes de analisar a Paisagem-Sonora envolvente e os movimentos do utilizador. Dois objectivos principais guiaram a produção desta ferramenta de investigação: recolher dados relativos à atividade cinética e sonora dos utilizadores e proporcionar a estes uma experiência real de utilização uma Rede Social Sonora, de modo a recolher opiniões fundamentadas sobre esta tipologia específica de socialização. A aplicação – Hurly-Burly – analisa a Paisagem-Sonora através de algoritmos de Audição Computacional, classificando- a de acordo com quatro categorias: diálogo (voz), música, sons ambientais (“ruídos”) e silêncio. Adicionalmente, determina o seu nível de pressão sonora em dB(A)eq. Esta informação é então distribuída pela rede social dos utilizadores, permitindo a cada elemento visualizar e ouvir uma representação do som analisado. É mantido num servidor Web um registo individual da informação sonora e cinética captada, o qual pode ser acedido através de uma aplicação Web que mostra o perfil sonoro de cada utilizador ao longo do tempo, numa visualização ao estilo linha-temporal. O procedimento experimental incluiu três grupos de teste distintos, formando cada um a sua própria rede social com coeficiente de aglomeração igual a um. Após a implementação da experiência e análise de resultados, concluímos que a Paisagem- Sonora pode desempenhar um papel no paradigma das Redes Sociais Em- Linha, em particular no que diz respeito à sua presença nos dispositivos móveis. Ficou provado que os dispositivos móveis comerciais da atualidade apresentam-se com uma oportunidade promissora para desempenhar este tipo de tarefas (tais como: monitorização contínua, registo quotidiano e análise sensorial ambiental), mas as limitações relacionadas com a autonomia energética e funcionamento em multitarefa representam ainda um constrangimento que impede a sua massificação. Além disso, a privacidade no mundo virtual é algo que os utilizadores atuais não estão dispostos a abdicar: partilhar continuamente a Paisagem-Sonora real em detrimento de uma representação de alto nível é algo que refrearia os utilizadores de usar a aplicação. Também demonstrámos que os utilizadores que mais conhecedores do fenómeno da Paisagem-Sonora são também os que consideram esta como importante no contexto das Redes Sociais Em-Linha. Isso significa que uma atitude pedagógica em relação ao fenómeno sonoro é essencial para obter dele o maior ganho possível. Esta investigação propõe-se a dar um passo em frente nessa direção