A New Exponentiation Algorithm Resistant to Combined Side Channel Attack

Abstract Since two different types of side channel attacks based on passive information leakage and active fault injection are independently considered as implementation threats on cryptographic modules, most countermeasures have been separately developed according to each attack type. But then, Amiel et al. proposed a combined side channel attack in which an attacker combines these two methods to recover the secret key in an RSA implementation. In this paper, we show that the BNP (Boscher, Naciri, and Prouff) algorithm for RSA, which is an SPA/FA-resistant exponentiation method, is also vulnerable to the combined attack. In addition, we propose a new exponentiation algorithm resistant to power analysis and fault attack as well as the combined attack. The proposed secure exponentiation algorithm can be employed to strengthen the security of CRT-RSA

Synergistic Amplification of Oxygen Generation in (Photo)Catalytic Water Splitting by a PEDOT/Nano-Co3O4/MWCNT Thin Film Composite

2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Amplifying catalysis by thoughtful exploitation of synergistic effects with interacting supports is a new field of potentially great significance. It is particularly relevant for solar-assisted reactions that are currently too poorly catalyzed to be practically viable, such as photoelectrochemical splitting of water to produce hydrogen and oxygen. In this work we describe synergistic amplification of water oxidation photoelectrocatalysis by the use of a thin layer electroactive polymer support. Coating of a bare Pt surface with a 0.98 μm thick film of poly(3,4-ethylene-dioxythiophene) (PEDOT) containing a specific molar ratio of nano-Co3O4 (a water oxidation catalyst) and multi-wall carbon nanotubes (oxidatively stable conductors) synergistically amplifies its rate of water oxidation catalysis by 15-fold (under the most oxidizing conditions that can be applied to PEDOT without degradation; with light illumination of 0.25 sun). To the best of our knowledge, this film is the most active water oxidation catalyst yet reported under near-neutral (pH 12) conditions as a proportion of the activity of Pt, which is the industry-standard catalyst of the reaction

Synergistic Amplification of Water Oxidation Catalysis on Pt by a Thin-Film Conducting Polymer Composite

Despite their potential for facilitating high activity, thin-film conducting polymer supports have, historically, expedited only relatively weak performances in catalytic water oxidation (with current densities in the μA/cm2 range). In this work, we have investigated the conditions under which thin-film conducting polymers may synergistically amplify catalysis. A composite conducting polymer film has been developed that, when overcoated on a bare Pt electrode, amplifies its catalytic performance by an order of magnitude (into the mA/cm2 range). When poised at 0.80 V (vs Ag/AgCl) at pH 12, a control, bare Pt electrode yielded a current density of 0.15 mA/cm2 for catalytic water oxidation. When then overcoated with a composite poly(3,4-ethylenedioxythiophene) (PEDOT) film containing nanoparticulate Ni (nano-Ni) catalyst and reduced graphene oxide (rGO) conductor in the specific molar ratio of 4.5 (C; PEDOT): 1 (Ni): 9.5 (C; other), the electrode generated water oxidation current densities of 1.10-1.15 mA/cm2 under the same conditions (over \u3e50 h of operation; including a photocurrent of 0.55 mA/cm2 under light illumination of 0.25 sun). Control films containing other combinations of the above components, yielded notably lower currents. These conditions represent the most favorable for water oxidation at which PEDOT does not degrade. Studies suggested that the above composite contained an optimum ratio of catalyst density to conductivity and thickness in which the PEDOT electrically connected the largest number of catalytic sites (thereby maximizing the catalytically active area) by the shortest, least-resistive pathway (thereby minimizing the Tafel slope). That is, the amplification appeared to be created by a synergistic matching of the connectivity, conductivity, and catalytic capacity of the film. This approach provides a potential means for more effectively deploying thin-film conducting polymers as catalyst supports

A Porphyrin/Graphene Framework: A Highly Efficient and Robust Electrocatalyst for Carbon Dioxide Reduction

Developing immobilized molecular complexes, which demonstrate high product efficiencies at low overpotential in the electrochemical reduction of CO2in aqueous media, is essential for the practical production of reduction products. In this work, a simple and facile self-assembly method is demonstrated by electrostatic interaction and π-π stacking for the fabrication of a porphyrin/graphene framework (FePGF) composed of Fe(III) tetraphenyltrimethylammonium porphyrin and reduced liquid crystalline graphene oxide that can be utilized for the electrocatalytic reduction of CO2to CO on a glassy carbon electrode in aqueous electrolyte. The FePGF results in an outstanding robust catalytic performance for the production of CO with 97.0% faradaic efficiency at an overpotential of 480 mV and superior long-term stability relative to other heterogeneous molecular complexes of over 24 h (cathodic energy efficiency: 58.1%). In addition, a high surface area carbon fiber paper is used as a substrate for FePGF catalyst, resulting in enhanced current density of 1.68 mA cm-2with 98.7% CO faradaic efficiency at an overpotential of 430 mV for 10 h, corresponding to a turnover frequency of 2.9 s-1and 104 400 turnover number. Furthermore, FePGF/CFP has one of the highest cathodic energy efficiencies (60.9%) reported for immobilized metal complex catalysts

Synergistic amplification of (photo)catalytic oxygen and hydrogen generation from water by thin-film polypyrrole composites

© 2020 Elsevier B.V. Thin films of polypyrrole (PPy) containing nano-Ni (\u27nano-Ni’) (as catalyst) and reduced graphene oxide (rGO) (as conductor) have been studied as (photo)electrocatalysts of the oxygen (O2)-evolution reaction (OER) (at 0.8 V vs Ag/AgCl, in 0.2M Na2SO4, pH 12) and the hydrogen (H2)-evolution reaction (HER) (at -0.75 V vs Ag/AgCl, in 0.05M H2SO4/0.2M Na2SO4) under light illumination of 0.25 sun. The above conditions were the most favorable for O2/H2-evolution under which the PPy and/or the nano-Ni constituents were not degraded. The industry benchmark catalyst, bare Pt, generated 0.15 mA/cm2 for O2-evolution and 2.2 mA/cm2 for H2-evolution under the above conditions. However, when the Pt was coated with PPy containing nano-Ni, and rGO in optimum molar ratios, it generated catalytic current densities that were 670 % larger for O2-generation (0.97–1.0 mA/cm2, including a photocurrent of 0.48 mA/cm2) and 18 % larger for H2-generation (2.38–2.60 mA/cm2, including a photocurrent of 0.20−0.40 mA/cm2), over periods of up to 50 h. EIS and Tafel plots indicated that these remarkable synergic amplifications derived from the combination of a high density of catalytic sites with the least-resistive conduction pathways, on average, within the coating. As catalytic accelerations of this type have previously only been observed with poly(3,4-ethylenedioxythiophene) (PEDOT), these results indicate that the principles of synergistic amplification also apply to other conducting polymer supports

A comparative investigation of carbon black (Super-P) and vapor-grown carbon fibers (VGCFs) as conductive additives for lithium-ion battery cathodes

To investigate the synergistic effect of different types of conductive additives on the cathode performance of lithium-ion batteries, various types of cathode materials containing different ratios of vapor-grown carbon fibers (VGCFs) and carbon black (Super-P) are investigated. The pillar-like morphology of the VGCFs enabled them to efficiently connect to the active materials and hence, the highest electrical conductivity of LiCoO2 and LiFePO4 (both of which are composed of primary particles) was achieved with the VGCFs. On the other hand, for LiNi0.6Co0.2Mn0.2O2, composed of micro-sized secondary particles embedded with nano-sized primary particles, improved electrical conductivity was achieved with a mixture of VGCF and Super-P via synergistic action

Mechanical robustness of composite electrode for lithium ion battery: Insight into entanglement & crystallinity of polymeric binder

To investigate the correlation between the molecular weight of the polymeric binder in Li-ion battery electrodes and their adhesion properties, polyvinylidene fluoride (PVdF) with three different molecular weights of 500,000, 630,000, and 1,000,000 are selected for LiCoO2 electrode fabrication. Using a surface and interfacial cutting analysis system, it is observed that, as the molecular weight of the PVdF increases, the adhesion strength not only in the electrode composite, but also at the electrode/current collector interface increases. This enhancement can be attributed to the increased polymeric chain entanglement and higher crystallinity of PVdF with higher molecular weight, which is confirmed using a microfluidic viscometer and differential scanning calorimeter, respectively. In summary, regardless of slightly higher electrode resistance, the LiCoO2 electrode with a PVdF binder of high molecular weight shows better electrochemical performance during cycling test even at 60 °C due to its stable mechanical integrity. © 2019 Elsevier Ltd1

High performance Fe porphyrin/ionic liquid co-catalyst for electrochemical CO2 reduction

The efficient and selective catalytic reduction of CO2 is a highly promising process for both of the storage of renewable energy as well as the production of valuable chemical feedstocks. In this work, we show that the addition of an ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, in an aprotic electrolyte containing a proton source and FeTPP, promotes the in situ formation of the [Fe0TPP]2− homogeneous catalyst at a less negative potential, resulting in lower overpotentials for the CO2 reduction (670 mV) and increased kinetics of electron transfer. This co-catalysis exhibits high Faradaic efficiency for CO production (93 %) and turnover number (2 740 000 after 4 hour electrolysis), with a four-fold increase in turnover frequency (TOF) when compared with the standard system without the ionic liquid