14 research outputs found
A Survey of Fast Scalar Multiplication on Elliptic Curve Cryptography for Lightweight Embedded Devices
Elliptic curve cryptography (ECC) is one of the most famous asymmetric cryptographic schemes which offers the same level of security with much shorter keys than the other widely used asymmetric cryptographic algorithm, Rivest, Shamir, and Adleman (RSA). In ECC, the main and most heavily used operation is the scalar multiplication kP, where the scalar value k is a private integer and must be secured. Various methods for fast scalar multiplication are based on the binary/ternary representation of the scalar. In this chapter, we present various methods to make fast scalar multiplication on ECC over prime field for lightweight embedded devices like wireless sensor network (WSN) and Internet of Things (IoT)
Fast Scalar Multiplication on Elliptic Curve Cryptography in Selected Intervals Suitable For Wireless Sensor Networks
International audienceIn Wireless Sensor Networks (WSNs), providing a robust security mechanism with limited energy resources is very challenging because of sensor node's limited resources (computation, bandwidth, memory). Asymmetric-key can fulfill the requirement, but if the number of nodes is large, symmetric-key cryptography is the best natural method because of its scalability. Asymmetric-key cryptography is power-hungry; nevertheless, Elliptic Curve Cryptosystems (ECC) are feasible and more flexible for sensor nodes. Scalar multiplication is the most widely used operation on ECC. Various methods for fast scalar multiplication exist, but they are based on the binary/ternary representation of the scalar. In this paper, we present a novel technique to make fast scalar multiplication on Elliptic Curve Cryptosystems over prime field for light-weight embedded devices like sensor nodes. Our method significantly reduces the computation of scalar multiplication by an equivalent representation of points based on point order in a given interval. Since our technique can act as a support for most existing methods, after an analytical and efficiency analysis, we implement and evaluate its performance in different scenari
Efficient authentication and cryptography algorithms for wirless sensor nerworks
Un rĂ©seau de capteurs sans fil (RCSF) est constituĂ© dâun grand nombre de nĆuds capteurs autonomes qui collaborent ensemble pour la surveillance dâune zone, dâune machine, dâune personne etc.. Dans certaines applications,les donnĂ©es critiques doivent ĂȘtre protĂ©gĂ©es contre toute utilisation frauduleuse et ĂȘtre accessibles en temps rĂ©el. Le besoin dâapporter une solution de sĂ©curitĂ© fiable et adaptĂ©e paraĂźt donc essentiel. Les solutions de sĂ©curitĂ© utilisĂ©es dans les rĂ©seaux traditionnels ne sont pas directement applicables dans les RCSFs, car dĂ©velopper des primitives de sĂ©curitĂ© en utilisant de faibles ressources devient un vĂ©ritable dĂ©fi. Dans cette thĂšse, nous proposons des solutions nouvelles peu gourmandes en ressources qui tiennent compte des faibles capacitĂ©s de dĂ©fense dâun rĂ©seau autonome. Dans cette optique nous appliquons des mĂ©canismes cryptographiques basÂŽes sur les fonctions de hachage et les courbes elliptiques. Un focus sur diffĂ©rents mĂ©canismes de sĂ©curitĂ© peu gourmands en ressources nous permet la mise en Ă©vidence des rapports de forces entre les RCSFs et leurs vulnĂ©rabilitĂ©s. Notre premiĂšre contribution vise `a amĂ©liorer la sĂ©curitĂ© et les performances en termes dâÂŽĂ©nergie sur des protocoles dâauthentification existants tout en utilisant les mĂȘmes mĂ©canismes. Dans la deuxiĂšme contribution, on utilise le concept de probabilitĂ© de risque afin de dĂ©terminer la consommation Ă©nergĂ©tique dans diffĂ©rentes architectures de dĂ©ploiement. Dans la troisiĂšme contribution nous prĂ©sentons un nouveau mĂ©canisme dâaccĂ©lĂ©ration de la multiplication scalaire sur les courbes elliptiques dĂ©finies dans des corps finis premiers. Ce mĂ©canisme basÂŽe sur lâopposĂ© et lâordre dâun point, rĂ©duit le nombre dâopĂ©rations de points dans un intervalle donnĂ©, et prĂ©sente en plus lâavantage de pouvoir ĂȘtre combinĂ© avec les techniques existantes. Enfin dans notre derniĂšre contribution, nous nous sommes intĂ©ressĂ©s Ă lâaccĂ©lĂ©ration du calcul des points rĂ©sultants du partitionnement du scalaire qui introduisent des coĂ»ts additionnels de calcul et de stockage mĂ©moire. Nous comparons diffĂ©rentes formules de points existantes en mettant en Ă©vidence leur efficacitĂ©.A Wireless Sensor Network (WSN) consists of a large number of sensor nodes which collaborate so as tomonitor environnement. For various WSNsâ applications, the collected data should be protected by preventingunauthorized users from gaining the information. The need to find a reliable and adaptive security solution isvery important. Most current standard security protocols designed for traditional networks cannot be applieddirectly in WSN. For this reason, providing a variety of security functions with limited resources is a realchallenge. Our research work seeks to find secure efficient solutions that take into account the rather weakdefense of an autonomous network. In this way, we apply lightweight cryptography mechanisms based on hashfunction and elliptic curves. A focus on different security mechanisms and lightweight security algorithms canhighlight the strength ratio between WSNs and their vulnerabilities. Our first contribution is on a secure energyefficient solution, it uses the same mechanism and aims to enhance the security weaknesses of existing solutions.The second contribution uses the concept of probability risk analysis to show to which level the proposedsolution justifies the better energy consumption for a given network architecture. In the third contribution, wepresent a new technique to accelerate scalar multiplication on elliptic curves cryptography over prime field forlight-weight embedded devices like sensor nodes. Our method reduces the computation of scalar multiplicationby an equivalent representation of points based on point order in a given interval and can also act as a supportfor most existing methods. Finally our last contribution presents a fast pre-computation algorithm in a parallelscalar multiplication to avoid the storage of pre-computation points which requires extra memory. We alsoprovide a comparison of different formulas so as to find out their efficiency
Algorithmes d'authentification et de cryptographie efficaces pour les réseaux de capteurs sans fil
A Wireless Sensor Network (WSN) consists of a large number of sensor nodes which collaborate so as tomonitor environnement. For various WSNsâ applications, the collected data should be protected by preventingunauthorized users from gaining the information. The need to find a reliable and adaptive security solution isvery important. Most current standard security protocols designed for traditional networks cannot be applieddirectly in WSN. For this reason, providing a variety of security functions with limited resources is a realchallenge. Our research work seeks to find secure efficient solutions that take into account the rather weakdefense of an autonomous network. In this way, we apply lightweight cryptography mechanisms based on hashfunction and elliptic curves. A focus on different security mechanisms and lightweight security algorithms canhighlight the strength ratio between WSNs and their vulnerabilities. Our first contribution is on a secure energyefficient solution, it uses the same mechanism and aims to enhance the security weaknesses of existing solutions.The second contribution uses the concept of probability risk analysis to show to which level the proposedsolution justifies the better energy consumption for a given network architecture. In the third contribution, wepresent a new technique to accelerate scalar multiplication on elliptic curves cryptography over prime field forlight-weight embedded devices like sensor nodes. Our method reduces the computation of scalar multiplicationby an equivalent representation of points based on point order in a given interval and can also act as a supportfor most existing methods. Finally our last contribution presents a fast pre-computation algorithm in a parallelscalar multiplication to avoid the storage of pre-computation points which requires extra memory. We alsoprovide a comparison of different formulas so as to find out their efficiency.Un rĂ©seau de capteurs sans fil (RCSF) est constituĂ© dâun grand nombre de nĆuds capteurs autonomes qui collaborent ensemble pour la surveillance dâune zone, dâune machine, dâune personne etc.. Dans certaines applications,les donnĂ©es critiques doivent ĂȘtre protĂ©gĂ©es contre toute utilisation frauduleuse et ĂȘtre accessibles en temps rĂ©el. Le besoin dâapporter une solution de sĂ©curitĂ© fiable et adaptĂ©e paraĂźt donc essentiel. Les solutions de sĂ©curitĂ© utilisĂ©es dans les rĂ©seaux traditionnels ne sont pas directement applicables dans les RCSFs, car dĂ©velopper des primitives de sĂ©curitĂ© en utilisant de faibles ressources devient un vĂ©ritable dĂ©fi. Dans cette thĂšse, nous proposons des solutions nouvelles peu gourmandes en ressources qui tiennent compte des faibles capacitĂ©s de dĂ©fense dâun rĂ©seau autonome. Dans cette optique nous appliquons des mĂ©canismes cryptographiques basÂŽes sur les fonctions de hachage et les courbes elliptiques. Un focus sur diffĂ©rents mĂ©canismes de sĂ©curitĂ© peu gourmands en ressources nous permet la mise en Ă©vidence des rapports de forces entre les RCSFs et leurs vulnĂ©rabilitĂ©s. Notre premiĂšre contribution vise `a amĂ©liorer la sĂ©curitĂ© et les performances en termes dâÂŽĂ©nergie sur des protocoles dâauthentification existants tout en utilisant les mĂȘmes mĂ©canismes. Dans la deuxiĂšme contribution, on utilise le concept de probabilitĂ© de risque afin de dĂ©terminer la consommation Ă©nergĂ©tique dans diffĂ©rentes architectures de dĂ©ploiement. Dans la troisiĂšme contribution nous prĂ©sentons un nouveau mĂ©canisme dâaccĂ©lĂ©ration de la multiplication scalaire sur les courbes elliptiques dĂ©finies dans des corps finis premiers. Ce mĂ©canisme basÂŽe sur lâopposĂ© et lâordre dâun point, rĂ©duit le nombre dâopĂ©rations de points dans un intervalle donnĂ©, et prĂ©sente en plus lâavantage de pouvoir ĂȘtre combinĂ© avec les techniques existantes. Enfin dans notre derniĂšre contribution, nous nous sommes intĂ©ressĂ©s Ă lâaccĂ©lĂ©ration du calcul des points rĂ©sultants du partitionnement du scalaire qui introduisent des coĂ»ts additionnels de calcul et de stockage mĂ©moire. Nous comparons diffĂ©rentes formules de points existantes en mettant en Ă©vidence leur efficacitĂ©
A User Authentication-Based Probabilistic Risk Approach for Wireless Sensor Networks
International audienceSensor nodes are low power devices which have limited computing resources. For various sensor network applications, providing a variety of security functions with limited energy resources and low power capabilities is a very big challenge. Recently, Vaidya et al. proposed an Improved Robust Dynamic User Authentication Scheme for Wireless Sensor Networks (WSNs) that allows legitimate users to query sensor data at every sensor node of the network. In this work, we show that, Vaidya et al.'s scheme suffers from the risk of forgery attacks and Denial-of-Service (DoS) attacks. To cope with them, we propose a new solution which is quite adequate for power and resource constrained sensor networks. The proposed scheme not only retains all the advantages in Vaidya et al.'s scheme but also protects against DoS and forgery attacks. After an evaluation of the energy cost based on the computational complexity, we use in our implementation the probability risk analysis owing to the DoS attack model to show to which level the proposed solution justifies the better energy consumption for a given network architecture
Photocatalyzed (3+2) Cycloaddition for the Dearomatization of ElectronâPoor Arenes under Flow Conditions
International audienceAbstract The photocatalyzed dearomative reaction between various electronâdeficient aromatic compounds and a nonâstabilized azomethine ylide is successfully performed in a flow system. Whereas the use of supported eosin as organic photocatalyst exhibits limited efficiency, turning to the soluble Rose Bengal allows to transform a broad range of substrates from hetarenes (indole, benzofuran, quinoline, pyridine) to naphthalenes and benzenes. This photocatalyzed (3+2) dearomative cycloaddition under green light irradiation provides a simple and efficient access to tridimensional pyrrolidino scaffolds with a tetrasubstituted carbon center at ring junction and can be performed in the friendly ethyl acetate. Computational studies support the mechanism involving azomethine ylide as reactive species toward the electronâpoor arene
Xaar ma
Senegalese version of international release of the album of the same name, featuring Vivian in a duet with Youssou N'Dour, energetic tama playing,Sengalese percussion, balafon,n'goni, and including western style guitar, drum and keyboar