Differential electromagnetic attack on an FPGA implementation of elliptic curve cryptosystems

This paper describes a differential electromagnetic analysis attack performed on a hardware implementation of an elliptic curve cryptosystem. We describe the use of the distance of mean test. The number of measurements needed to get a clear idea of the right guess of the key-bit is taken as indication of the success of the attack. We can find the right key-bit by using only 2000 measurements. Also we give a electromagnetic model for the FPGA we use in our experiments. The amplitude, the direction and the position of the current on the FPGA’s lines with respect to the position of the antenna have an influence on the measured electromagnetic radiation in the FPGA’s surrounding area

The phase diagram of magnetic ladders constructed from a composite-spin model

White's density matrix renormalization group ({DMRG}) method has been applied to an $S= 1/2 + 1/2$ composite-spin model, which can also be considered as a two-leg ladder model. By appropriate choices of the coupling constants this model allows not only to study how the gap is opened around the gapless integrable models, but also to interpolate continuously between models with different spin lengths. We have found indications for the existence of several different massive phases.Comment: 30 pages, 8 Postscript figure

Entanglement Measures for Single- and Multi-Reference Correlation Effects

Electron correlation effects are essential for an accurate ab initio description of molecules. A quantitative a priori knowledge of the single- or multi-reference nature of electronic structures as well as of the dominant contributions to the correlation energy can facilitate the decision regarding the optimum quantum chemical method of choice. We propose concepts from quantum information theory as orbital entanglement measures that allow us to evaluate the single- and multi-reference character of any molecular structure in a given orbital basis set. By studying these measures we can detect possible artifacts of small active spaces.Comment: 14 pages, 4 figure

The James Webb Space Telescope Mission

Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least $4m$. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the $6.5m$ James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

Experimental investigation of impact of addition of bioethanol in different biodiesels, on performance, combustion and emission characteristics

This study includes the experimental evaluation of performance, combustion and emission characteristics of cottonseed and grapeseed biodiesels and blends containing bioethanol in a diesel engine with different engine speeds at full load. Addition of bioethanol into the fuels (diesel and biodiesel) used by diesel engines is considered an effective solution. The study observed that the cetane number, viscosity, density and lower heating value of fuel were reduced after the addition of bioethanol in all engine speeds. While the brake power and torque values were reduced as the rate of bioethanol increased, additionally specific fuel consumption, maximum cylinder pressure, heat release and ignition delay also increased. Reviewing the emission results, carbon monoxide (CO) and total hydrocarbon (THC) emissions increased as bioethanol rate increased, nitrogen oxides (NO x ) and smoke emissions were reduced. © 2017, The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany, part of Springer Nature

The effects on performance, combustion and emission characteristics of DICI engine fuelled with TiO2 nanoparticles addition in diesel/biodiesel/n-butanol blends

In this study, waste cooking oil biodiesel was mixed with titanium dioxide (TiO2), a metal-based nano particle, and n-butanol (C4H9OH) along with euro diesel to examine their effects on diesel engines. Various ratio of fuel blends were prepared with TiO2 nano particles-diesel-biodiesel and n-butanol. The tests fuels were euro diesel (D100), biodiesel (B100), B20, B20 + TiO2, B20But10 and B20But10 + TiO2, respectively. Thermo-physical properties such as density, pour point, cloud point, cold filter clogging point, flash point and kinematic viscosity of all test fuels were determined followed by investigating engine performance parameters such as torque, power, fuel consumption and etc. Combustion analysis was also investigated. In addition, the effects on emissions such as CO, CO2, HC, NO and smoke opacity were also carried out. The addition of n-butanol to the fuel blends substantially affected density, kinematic viscosity and cold flow properties, while the addition of TiO2 has not much effect on these properties. For all tested fuels, the maximum brake engine torque and power were recorded at approximately 1400 rpm and 2800 rpm, respectively. The addition of TiO2 increased the brake engine torque and power 10.20% and 9.74% and decreased the brake specific fuel consumption 27.73% and 28.37%, respectively compared to blends without TiO2 additive. TiO2 additive increases the maximum cylinder pressure and heat release rate, as a result improved the engine performance and combustion. The addition of n-butanol in the fuel blend increased the maximum cylinder pressure and heat release rate values in comparison to euro diesel. The results of exhaust emission showed a decrease in CO, HC and smoke opacity emissions, whereas increased CO2 and NO emission, except the use of n-butanol reduced the values of NO emission, in comparison to euro diesel and without TiO2 additive. The results show that biodiesel produced from waste cooking oil, n-butanol and TiO2 additive can be used in diesel engines at certain proportion and that the additive materials improve the combustion characteristics, engine performance and exhaust gas emission. © 2018 Elsevier Lt