From Substitution Box To Threshold

With the escalating demand for lightweight ciphers as well as side channel protected implementation of those ciphers in recent times, this work focuses on two aspects. First, we present a tool for automating the task of finding a Threshold Implementation (TI) of a given Substitution Box (SBox). Our tool returns `with decomposition\u27 and `without decomposition\u27 based TI. The `with decomposition\u27 based implementation returns a combinational SBox; whereas we get a sequential SBox from the `without decomposition\u27 based implementation. Despite being high in demand, it appears that this kind of tool has been missing so far. Second, we show an algorithmic approach where a given cipher implementation can be tweaked (without altering the cipher specification) so that its TI cost can be significantly reduced. We take the PRESENT cipher as our case study (our methodology can be applied to other ciphers as well). Indeed, we show over 31 percent reduction in area and over 52 percent reduction in depth compared to the basic threshold implementation

BAKSHEESH: Similar Yet Different From GIFT

We propose a lightweight block cipher named BAKSHEESH, which follows up on the popular cipher GIFT-128 (CHES\u2717). BAKSHEESH runs for 35 rounds, which is 12.50 percent smaller compared to GIFT-128 (runs for 40 rounds) while maintaining the same security claims against the classical attacks. The crux of BAKSHEESH is to use a 4-bit SBox that has a non-trivial Linear Structure (LS). An SBox with one or more non-trivial LS has not been used in a cipher construction until DEFAULT (Asiacrypt\u2721). DEFAULT is pitched to have inherent protection against the Differential Fault Attack (DFA), thanks to its SBox having 3 non-trivial LS. BAKSHEESH, however, uses an SBox with only 1 non-trivial LS; and is a traditional cipher just like GIFT-128, with no claims against DFA. The SBox requires a low number of AND gates, making BAKSHEESH suitable for side channel countermeasures (when compared to GIFT-128) and other niche applications. Indeed, our study on the cost of the threshold implementation shows that BAKSHEESH offers a few-fold advantage over other lightweight ciphers. The design is not much deviated from its predecessor (GIFT-128), thereby allowing for easy implementation (such as fix-slicing in software). However, BAKSHEESH opts for the full-round key XOR, compared to the half-round key XOR in GIFT. Thus, when taking everything into account, we show how a cipher construction can benefit from the unique vantage point of using 1 LS SBox, by combining the state-of-the-art progress in classical cryptanalysis and protection against device-dependent attacks. We, therefore, create a new paradigm of lightweight ciphers, by adequate deliberation on the design choice, and solidify it with appropriate security analysis and ample implementation/benchmark

Enhancement of flexibility of conventional Hydro Power Plants for faster ramp-rate using Energy Storage Systems

Avec la croissance de la production d'électricité et les préoccupations croissantes concernant la dégradation du climat, la demande de sources d'énergie renouvelables (SER) augmente simultanément. La dépendance des SER telles que l'énergie solaire photovoltaïque et l'énergie éolienne vis-à-vis de la nature rend la production de ces sources très intermittente. En outre, ces sources d'énergie électrique font appel à des moyens de production non synchrones. Cependant, à mesure que de plus en plus de SER sont ajoutées au réseau, l'inertie globale du réseau diminue progressivement. La perte d'inertie du réseau menace la stabilité et la sécurité des réseaux électriques. Afin d'atténuer ces effets, les services auxiliaires se développent dans le monde entier auprès de différentes entreprises de production, de transport et de distribution d'électricité. Ces services de réseau sont classés en services de fréquence et de tension. Les services de fréquence sont contrôlés par la régulation de la puissance active et les services de tension sont contrôlés par la puissance réactive. Diverses recherches sont menées dans le monde entier pour proposer différents moyens d'atténuer les effets de l'augmentation des SER. L'un de ces moyens consiste à augmenter la flexibilité du système électrique. Pour ce faire, les sources d'énergie conventionnelles peuvent jouer un rôle très important. Cependant, en raison de contraintes physiques, toutes les centrales conventionnelles ne sont pas en mesure de répondre à l'évolution rapide de la demande du réseau. Dans ce cas, la centrale hydroélectrique (HPP) peut constituer la solution la plus intéressante car elle est à la fois renouvelable et capable de suivre la demande de la charge. De plus, comme les centrales hydroélectriques fournissent de l'énergie à l'humanité depuis très longtemps, plusieurs travaux de recherche et développement ont été menés pour rendre leurs fonctionnalités et leurs opérations de plus en plus efficaces. Avec le besoin croissant de flexibilité et les préoccupations climatiques, il devient impératif d'améliorer les capacités des sources de génération qui sont moins polluantes et en même temps peuvent fournir les services désirés. Dans cette optique, ce travail se concentre sur l'amélioration de la flexibilité des centrales hydroélectriques conventionnelles en augmentant leur temps de réponse par des taux de rampe améliorés en utilisant un système de stockage d'énergie (ESS). Pour atteindre cet objectif, des modèles mathématiques sont développés à la fois pour l'ESS et la centrale hydroélectrique. Les objectifs d'amélioration du taux de rampe sont décrits en détail. Avec ces objectifs, deux approches d'optimisation différentes sont acquises où dans l'une, seule l'opération ESS est optimisée pour atteindre les objectifs et dans la seconde, les opérations ESS et HPP sont optimisées. Plusieurs scénarios ont été identifiés pour lesquels les tests doivent être effectués. De plus, pour analyser l'impact du dimensionnement de l'ESS, différentes tailles ont été utilisées pour chaque test. Une étude comparative est menée pour les deux méthodes et les déductions sont tirées en détail dans ce travail. Une fois le processus de simulation et l'interprétation des résultats terminés, les résultats sont utilisés pour réaliser une expérience avec un Power-Hardware-In-Loop (PHIL) où un superviseur et un contrôleur sont conçus pour contrôler le circuit hydraulique physique avec les paramètres du processus de simulation. Une fois les expériences terminées, les données de simulation et expérimentales sont comparées et des conclusions sont tirées indiquant la possibilité d'augmenter le taux de rampe de la centrale hydroélectrique à l'aide d'un ESS.With growth in electric power generation and growing concerns about climate degradation, more demand of renewable energy sources (RES) is simultaneously increasing. The dependence of RES such as solar photovoltaic and wind power on nature makes the production of these sources highly intermittent. In addition, these electrical energy sources do non-synchronous means of generation. However, as more and more RES are added to the grid, the overall grid inertia gradually decreases. The loss of grid inertia threatens the stability and security of electrical grids. In order to mitigate these effects, ancillary services are expanding worldwide with different power generation, transmission and distribution companies. These grid services are classified into frequency and voltage services. Frequency services are controlled by active power control and voltage services are controlled by reactive power. Various researches are being conducted worldwide to propose different ways to mitigate these effects of increasing RESs. One such means is to increase the flexibility of power system. To increase flexibility, conventional power sources can play a very important role, however, due to physical constraints, not all conventional power plants are able to meet fast changing demands of the grid. In this case, hydro power plant (HPP) may provide the most interesting solution as it is both renewable and able to follow the load demand. Moreover, as hydroelectric power plants have been providing energy to mankind for a very long time, several research and development works have been conducted to make their functionalities and operations more and more efficient. With the increasing need for flexibility and climate concerns, it becomes imperative to improve the capabilities of generation sources that are less polluting and at the same time can provide the desired services. With this in mind, this work focuses on improving the flexibility of conventional hydroelectric power plants by increasing their response time through improved ramp rates using an energy storage system (ESS). To achieve this objective, mathematical models are developed for both ESS and HPP. The objectives for ramp rate improvement are described in detail. With these objectives, two different optimization approaches are acquired where in one, only the SSE operation is optimized to achieve the objectives and in the second, both the SSE and HPP operations are optimized. Several scenarios have been identified for which the tests need to be performed. In addition, to analyze the impact of SSE sizing, different sizes were used for each test. A comparative study is conducted for both methods and inferences are drawn in detail in this work. Once the simulation process and interpretation of the results are completed, the results are used to perform an experiment with a Power-Hardware-In-Loop (PHIL) where a supervisor and controller are designed to control the physical hydraulic circuit with the parameters of the simulation process. Once the experiments are completed, the simulation and experimental data are compared and conclusions are drawn indicating the possibility of increasing the ramp rate of the hydro plant using an ESS

Understanding Microgrids and Their Future Trends

International audienceDepletion of natural resources to meet power demands has revolutionized the use of Renewable Energy Sources (RESs).The paradigm shift from the centralized to distributed control is witnessed due to the Microgrids. Different configurations using smart grids and Microgrids are expected to ensure grid stability and security.Eventually, electricity market is subjected to change due to the projected changes in the grid architecture. This paper is a review on the Microgrids, its elements and the controllability. This paper discusses the major issues in the Microgrids, the factors affecting the choice of the Microgrid type and also various generation sources and their combination for reliable power quality and control. Recent developments with future trends are also addressed in this paper

Understanding Microgrids and Their Future Trends

International audienceDepletion of natural resources to meet power demands has revolutionized the use of Renewable Energy Sources (RESs).The paradigm shift from the centralized to distributed control is witnessed due to the Microgrids. Different configurations using smart grids and Microgrids are expected to ensure grid stability and security.Eventually, electricity market is subjected to change due to the projected changes in the grid architecture. This paper is a review on the Microgrids, its elements and the controllability. This paper discusses the major issues in the Microgrids, the factors affecting the choice of the Microgrid type and also various generation sources and their combination for reliable power quality and control. Recent developments with future trends are also addressed in this paper

Frequency Control Using V2G and Synchronous Power Controller based HVDC Links in Presence of Wind and PV Units

International audienceThe world is shifting towards Renewable Energy Sources (RES) to meet the increasing demand. With proportionally high penetration of RES, the inertia of the grid tends to fall due to the incapability of these sources to participate in control mechanism. Also, due to the indeterminacy in the generation pattern, they tend to feed small signal disturbances in the grid due to the imbalance of generation and demand, which affects the frequency stability. In this paper, the affect of inertia emulation (IE) in the grid is presented to mitigate the small signal disturbances caused due to the change in load or due to the penetration of the RES. This work has considered Electric Vehicles for the application of vehicle to grid (V2G) towards frequency control. A cooperative control method, with V2G and synchronous power controller (SPC) based HVDC links, has been proposed towards the control of the fluctuations and a considerable decrease in the deviations have been observed. Several case studies are conducted and the results are presented to proof the concept

An overview of Hybridization of Power sources for Ancillary Service

International audienceIncreasing Renewable Energy Sources (RESs) mix in the power grids, with advanced power electronic converters are not only bringing green energy to meet the demands but also are posing threats to the power system because of their impacts on the frequency/voltage stability and short circuit current mitigation issues. Obviously, with large hydro storage systems like the Pumped Storage Plants (PSPs) or other storage technologies, problems can be met with solutions increasing the grid stability and reliability. But the characteristics of different technologies does make the decision challenging. This paper gives an overview of how hybridization of power sources using different storage technologies can mitigate the impacts of the RES penetration into the grid

An overview of Hybridization of Power sources for Ancillary Service

International audienceIncreasing Renewable Energy Sources (RESs) mix in the power grids, with advanced power electronic converters are not only bringing green energy to meet the demands but also are posing threats to the power system because of their impacts on the frequency/voltage stability and short circuit current mitigation issues. Obviously, with large hydro storage systems like the Pumped Storage Plants (PSPs) or other storage technologies, problems can be met with solutions increasing the grid stability and reliability. But the characteristics of different technologies does make the decision challenging. This paper gives an overview of how hybridization of power sources using different storage technologies can mitigate the impacts of the RES penetration into the grid

An overview of Hybridization of Power sources for Ancillary Service

International audienceIncreasing Renewable Energy Sources (RESs) mix in the power grids, with advanced power electronic converters are not only bringing green energy to meet the demands but also are posing threats to the power system because of their impacts on the frequency/voltage stability and short circuit current mitigation issues. Obviously, with large hydro storage systems like the Pumped Storage Plants (PSPs) or other storage technologies, problems can be met with solutions increasing the grid stability and reliability. But the characteristics of different technologies does make the decision challenging. This paper gives an overview of how hybridization of power sources using different storage technologies can mitigate the impacts of the RES penetration into the grid

Side-Channel Evaluation Methodology on Software

Cryptographic implementations need to be robust amidst the widespread use of crypto-libraries and attacks targeting their implementation, such as side-channel attacks (SCA). Many certification schemes, such as Common Criteria and FIPS 140, continue without addressing side-channel flaws. Research works mostly tackle sophisticated attacks with simple use-cases, which is not the reality where end-to-end evaluation is not trivial. In this study we used all due diligence to assess the invulnerability of a given implementation from the shoes of an evaluator. In this work we underline that there are two kinds of SCA: horizontal and vertical. In terms of quotation, measurement and exploitation, horizontal SCA is easier. If traces are constant-time, then vertical attacks become convenient, since there is no need for specific alignment (“value based analysis”). We introduce our new methodology: Vary the key to select sensitive samples, where the values depend upon the key, and subsequently vary the mask to uncover unmasked key-dependent leakage, i.e., the flaws. This can be done in the source code (pre-silicon) for the designer or on the actual traces (post-silicon) for the test-lab. We also propose a methodology for quotations regarding SCA unlike standards that focus on only one aspect (like number of traces) and forgets about other aspects (such as equipment; cf. ISO/IEC 20085-1