Quantum-secure message authentication via blind-unforgeability

Formulating and designing unforgeable authentication of classical messages in the presence of quantum adversaries has been a challenge, as the familiar classical notions of unforgeability do not directly translate into meaningful notions in the quantum setting. A particular difficulty is how to fairly capture the notion of "predicting an unqueried value" when the adversary can query in quantum superposition. In this work, we uncover serious shortcomings in existing approaches, and propose a new definition. We then support its viability by a number of constructions and characterizations. Specifically, we demonstrate a function which is secure according to the existing definition by Boneh and Zhandry, but is clearly vulnerable to a quantum forgery attack, whereby a query supported only on inputs that start with 0 divulges the value of the function on an input that starts with 1. We then propose a new definition, which we call "blind-unforgeability" (or BU.) This notion matches "intuitive unpredictability" in all examples studied thus far. It defines a function to be predictable if there exists an adversary which can use "partially blinded" oracle access to predict values in the blinded region. Our definition (BU) coincides with standard unpredictability (EUF-CMA) in the classical-query setting. We show that quantum-secure pseudorandom functions are BU-secure MACs. In addition, we show that BU satisfies a composition property (Hash-and-MAC) using "Bernoulli-preserving" hash functions, a new notion which may be of independent interest. Finally, we show that BU is amenable to security reductions by giving a precise bound on the extent to which quantum algorithms can deviate from their usual behavior due to the blinding in the BU security experiment.Comment: 23+9 pages, v3: published version, with one theorem statement in the summary of results correcte

IXPE Mission System Concept and Development Status

The Goal of the Imaging X-Ray Polarimetry Explorer (IXPE) Mi SMEX), is to expand understanding of high-energy astrophysical processes and sources, in support of NASAs first science objective in Astrophysics: Discover how the universe works. IXPE, an international collaboration, will conduct X-ray imaging polarimetry for multiple categories of cosmic X-ray sources such as neutron stars, stellar-mass black holes, supernova remnants and active galactic nuclei. The Observatory uses a single science operational mode capturing the X-ray data from the targets. The IXPE Observatory consists of spacecraft and payload modules built up in parallel to form the Observatory during system integration and test. The payload includes three X-ray telescopes each consisting of a polarization-sensitive, gas pixel X-ray detector, paired with its corresponding grazing incidence mirror module assembly (MMA). A deployable boom provides the correct separation (focal length) between the detector units (DU) and MMAs. These payload elements are supported by the IXPE spacecraft which is derived from the BCP-small spacecraft architecture. This paper summarizes the IXPE mission science objectives, updates the Observatory implementation concept including the payload and spacecraft ts and summarizes the mission status since last years conference

How Power-to-Gas strategy could reduce national Natural Gas consumption over the energy crisis period

Europe is facing an energy crisis caused by the dramatic rise in gas prices. This situation is damaging the European economy and urgent measures to reduce gas consumption are crucial in the short term. This paper aims to analyse the potential contribution of the Power-to-Gas strategy to reduce the Italian consumption of Natural Gas (NG) in the context of the current energy crisis. To do so, the Italian energy system has been modelled by means the EnergyPLAN software. The electrolysers' installation in the Italian energy systems has been simulated in combination with different levels of additional RES installation. The hydrogen production and the NG abatement potential have been calculated in each simulated scenario. Furthermore, the Natural Gas Abatement Cost (NGAC) has been assessed. By installing 1.5 GW of electrolysers, along with an additional 25 GW of renewables, about 140 ktonH2/year can be produced only by exploiting the RES excess. The total NG reduction due to both the RES generation and the hydrogen injection is more than 60 TWh/year. The NG abatement cost varies between 45 and 54 €/MWh. At current gas prices, it is therefore extremely cheaper to invest in a drastic reduction of natural gas than to buy the same amount of gas on the wholesale market. Therefore, the current energy crisis can be an opportunity to accelerate the energy transition process. The proposed solutions allow a substantial reduction in gas consumption with the consequent reduction in emissions and the country's energy dependency

Assessment of the Optimal Energy Generation and Storage Systems to Feed a Districting Heating Network

Employing sustainable energy systems is a must fact of the current years. Urban districts can lead the decarbonization process of cities to allow the development of decentralization energy systems such as district heating. On the other hand, the exergy analysis combined with energy evaluation can be a suitable way to investigate the efficiency and flexibility of an energy system. In this framework, this study investigates the optimal energy and storage systems to feed a district heating network. Four types of energy systems were analyzed, such as boilers, cogeneration plants, solar systems and the combination of them. The size of the thermal energy storage of the network is investigated in terms of volume and temperature. In parallel, the exergy efficiency of all the systems was calculated. The optimal heating system configuration to feed the studied district heating is the cogeneration plant with solar collectors, according to both the temperature trend fluctuation and exergy efficiency of the system. Moreover, the employment of thermal energy storage is crucial to face the renewable energy source’s variability. As a further investigation, additional exergy indicators can be studied to underline the performances of such an decentralized energy system to increase the quality of the built environment

Interval prediction algorithm and optimal scenario making model for wind power producers bidding strategy

Nowadays, renewable energies are important sources for supplying electric power demand and a key entity of future energy markets. Therefore, wind power producers (WPPs) in most of the power systems in the world have a key role. On the other hand, the wind speed uncertainty makes WPPs deferent power generators, which in turn causes adequate bidding strategies, that leads to market rules, and the functional abilities of the turbines to penetrate the market. In this paper, a new bidding strategy has been proposed based on optimal scenario making for WPPs in a competitive power market. As known, the WPP generation is uncertain, and different scenarios must be created for wind power production. Therefore, a prediction intervals method has been improved in making scenarios and increase the accuracy of the presence of WPPs in the balancing market. Besides, a new optimization algorithm has been proposed called the grasshopper optimization algorithm to simulate the optimal bidding problem of WPPs. A set of numerical examples, as well as a case-study based on real-world data, allows illustrating and discussing the properties of the proposed method

Hydrogen blending in natural gas grid: energy, environmental, and economic implications in the residential sector

The forthcoming implementation of national policies towards hydrogen blending into the natural gas grid will affect the technical and economic parameters that must be taken into account in the design of building heating systems. This study evaluates the implications of using hydrogen-enriched natural gas (H2NG) blends in condensing boilers and Gas Adsorption Heat Pumps (GAHPs) in a residential building in Rome, Italy. The analysis considers several parameters, including non-renewable primary energy consumption, CO2 emissions, Levelized Cost of Heat (LCOH), and Carbon Abatement Cost (CAC). The results show that a 30% hydrogen blend achieves a primary energy consumption reduction of 12.05% and 11.19% in boilers and GAHPs, respectively. The presence of hydrogen in the mixture exerts a more pronounced influence on the reduction in fossil primary energy and CO2 emissions in condensing boilers, as it enhances combustion efficiency. The GAHP system turns out to be more cost-effective due to its higher efficiency. At current hydrogen costs, the LCOH of both technologies increases as the volume fraction of hydrogen increases. The forthcoming cost reduction in hydrogen will reduce the LCOH and the decarbonization cost for both technologies. At low hydrogen prices, the CAC for boilers is lower than for GAHPs; therefore, replacing boilers with other gas technologies rather than electric heat pumps increases the risk of creating stranded assets. In conclusion, blending hydrogen into the gas grid can be a useful policy to reduce emissions from the overall natural gas consumption during the process of end-use electrification, while stimulating the development of a hydrogen economy

Optimal decarbonisation pathways for the Italian energy system: Modelling a long-term energy transition to achieve zero emission by 2050

The goal of achieving a zero-emission energy system by 2050 requires accurate energy planning to minimise the overall cost of the energy transition. Long-term energy models based on cost-optimal solutions are extremely dependent on the cost forecasts of different technologies. However, such forecasts are inherently uncertain. The aim of the present work is to identify a cost-optimal pathway for the Italian energy system decarbonisation and assess how renewable cost scenarios can affect the optimal solution. The analysis has been carried out with the H2RES model, a single-objective optimisation algorithm based on Linear Programming. Different cost scenarios for photovoltaics, on-shore and off-shore wind power, and lithium-ion batteries are simulated. Results indicate that a 100% renewable energy system in Italy is technically feasible. Power-to-X technologies are crucial for balancing purposes, enabling a share of non-dispatchable generation higher than 90%. Renewable cost scenarios affect the energy mix, however, both on-shore and off-shore wind saturate the maximum capacity potential in almost all scenarios. Cost forecasts for lithium-ion batteries have a significant impact on their optimal capacity and the role of hydrogen. Indeed, as battery costs rise, fuel cells emerge as the main solution for balancing services. This study emphasises the importance of conducting cost sensitivity analyses in long-term energy planning. Such analyses can help to determine how changes in cost forecasts may affect the optimal strategies for decarbonising national energy systems

Energy modelling challenges for the full decarbonisation of hard-to-abate sectors

Many Countries have set extremely ambitious targets to speed up the energy transition and reach zero emission by 2050. This has gained even more important motifs in light of the recent geo-political events and the energy crisis that have been shaking the world balance and messing with the energy agendas of many Countries, especially those with a high reliance on imported fossil fuels. Thus, it has become ever more important to find solutions for the decarbonisation of every economic sector including also the “hard-to-abate” ones. Different solutions have been identified for the decarbonisation of such sectors that for their heterogeneity and specific requirements need sometimes unique technologies. Most proposed solutions entails a tighter connection to the power system either through direct or indirect electrification. This research wants to shade light on the most promising technologies, their impact and potential synergies with the entire energy system thus supporting Sustainable Development Goals 7, 8, 9 and 13. Furthermore, this review also discuss how the decarbonisation of hard-to-abate sectors is analysed in energy system modelling for energy planning purposes, what are the most used approaches and what each of them entails, critically discussing and analysing the main challenges while offering potential solutions to tackle them

The Imaging X-ray Polarimetry Explorer (IXPE): Technical Overview

The Imaging X-ray Polarimetry Explorer (IXPE) will expand the information space for study of cosmic sources, by adding linear polarization to the properties (time, energy, and position) observed in x-ray astronomy. Selected in 2017 January as a NASA Astrophysics Small Explorer (SMEX) mission, IXPE will be launched into an equatorial orbit in 2021. The IXPE mission will provide scientifically meaningful measurements of the x-ray polarization of a few dozen sources in the 2-8 keV band, including polarization maps of several x-ray-bright extended sources and phase-resolved polarimetry of many bright pulsating x-ray sources

Geodesy, geophysics and fundamental physics investigations of the BepiColombo mission

In preparation for the ESA/JAXA BepiColombo mission to Mercury, thematic working groups had been established for coordinating the activities within the BepiColombo Science Working Team in specific fields. Here we describe the scientific goals of the Geodesy and Geophysics Working Group (GGWG) that aims at addressing fundamental questions regarding Mercury’s internal structure and evolution. This multidisciplinary investigation will also test the gravity laws by using the planet Mercury as a proof mass. The instruments on the Mercury Planetary Orbiter (MPO), which are devoted to accomplishing the GGWG science objectives, include the BepiColombo Laser Altimeter (BELA), the Mercury orbiter radio science experiment (MORE), and the MPO magnetometer (MPO-MAG). The onboard Italian spring accelerometer (ISA) will greatly aid the orbit reconstruction needed by the gravity investigation and laser altimetry. We report the current knowledge on the geophysics, geodesy, and evolution of Mercury after the successful NASA mission MESSENGER and set the prospects for the BepiColombo science investigations based on the latest findings on Mercury’s interior. The MPO spacecraft of the BepiColombo mission will provide extremely accurate measurements of Mercury’s topography, gravity, and magnetic field, extending and improving MESSENGER data coverage, in particular in the southern hemisphere. Furthermore, the dual-spacecraft configuration of the BepiColombo mission with the Mio spacecraft at higher altitudes than the MPO spacecraft will be fundamental for decoupling the internal and external contributions of Mercury’s magnetic field. Thanks to the synergy between the geophysical instrument suite and to the complementary instruments dedicated to the investigations on Mercury’s surface, composition, and environment, the BepiColombo mission is poised to advance our understanding of the interior and evolution of the innermost planet of the solar system