연산자 조작 공격과 피연산자 조작 공격에 대한 기존 CRT-RSA Scheme의 안전성 분석

허순행(Soonhaeng Hur),이형섭(Hyungsub Lee),이현승(Hyunseung Rhee),최동현(Donghyun Choi),원동호(Dongho Won),김승주(Seungjoo Kim) 한국정보보호학회 2009 정보보호학회논문지 Vol.19 No.6

CRT-RSA의 사용이 대중화됨에 따라, CRT-RSA에 대한 보안 또한 중요 이슈가 되었다. 1996년, Bellcore 연구원들에 의해 CRT-RSA가 오류 주입 공격에 취약하다고 밝혀진 이래로, 많은 대응책들이 제안되었다. 첫 번째 대응책은 1999년 Shamir에 의해 제안되었으며, Shamir의 대응책은 오류 검사 기법에 기반을 두고 있다. Shamir의 대응책이 소개된 이후, 오류 검사 기법을 사용하는 많은 대응책들이 제안되었다. 그러나 Shamir의 대응책은 2001년 Joey 등에 의하여 피연산자 조작 공격에 취약함이 밝혀졌으며, 오류 검사 기법 또한 2003년 Yen 등에 의하여 연산자 조작 공격에 취약하다고 알려졌다. 이에 Yen 등은 오류 검사 기법을 사용하지 않고 오류 확산 기법을 사용하여 새로운 대응책을 제안하였으나, Yen 등이 제안한 대응책 또한 2007년에 Yen과 Kim에 의하여 안전하지 않음이 밝혀졌다. 최근에는 Kim 등이 Yen 등의 대응책을 보완한 새로운 대응책을 제안하였으며, Ha 등 또한 오류 확산 기법을 사용한 대응책을 제안하였다. 그러나 Kim 등과 Ha 등이 제안한 대응책들을 포함한 기존 대응책들은 연산자 조작 공격에 대해서는 안전성이 증명되지 않았기 때문에 본 논문에서는 피연산자 조작 공격은 물론, 연산자 조작 공격도 고려하여 지금까지 제안된 대응책들의 안전성을 분석할 것이다. As the use of RSA based on chinese remainder theorem(CRT-RSA) is being generalized, the security of CRT-RSA has been important. Since Bellcore researchers introduced the fault attacks on CRT-RSA, various countermeasures have been proposed. In 1999, Shamir firstly proposed a countermeasure using checking procedure. After Shamir's countermeasure was introduced, various countermeasures based on checking procedure have been proposed. However, Shamir's countermeasure was known to be vulnerable to the modified operand attack by Joey et al. in 2001, and the checking procedure was known to be vulnerable to the modified opcode attack by Yen et al. in 2003. Yen et al. proposed a new countermeasure without checking procedure, but their countermeasure was known to be also vulnerable to the modified operand attack by Yen and Kim in 2007. In this paper, we point out that pre, but countermeasures were vulnerable to the modified operand attack or the modified opcode attack.

Nano-graphite platelet loaded with LiFePO₄ nanoparticles used as the cathode in a high performance Li-ion battery

Kim, Haegyeom,Kim, Hyungsub,Kim, Sung-Wook,Park, Kyu-Young,Kim, Jinsoo,Jeon, Seokwoo,Kang, Kisuk Elsevier 2012 Carbon Vol.50 No.5

<P><B>Abstract</B></P><P>LiFePO<SUB>4</SUB> nanoparticles were grown on nano-graphite platelet (NGP) using a simple chemical route. The material was used as the cathode in Li-ion rechargeable batteries and exhibited excellent cyclability and rate capability because of the easy electron transport in it. The electrochemical stability of the electrode was improved by the two-dimensional conductive network of the NGP. The resulting electrodes delivered a specific capacity of about 150mAhg<SUP>−1</SUP> at a current rate of 135mAg<SUP>−1</SUP> (∼0.8C) after 100 cycles with no capacity fade. At elevated current rates, the electrodes exhibited capacities of more than 100mAhg<SUP>−1</SUP> at a current density of 2000mAg<SUP>−1</SUP> (∼12C) without further incorporation of conductivity agents or coatings.</P>

Neutron and X-ray Diffraction Study of Pyrophosphate-Based Li_2–<i>x</i>MP₂O₇ (M = Fe, Co) for Lithium Rechargeable Battery Electrodes

Kim, Hyungsub,Lee, Seongsu,Park, Young-Uk,Kim, Haegyeom,Kim, Jongsoon,Jeon, Seokwoo,Kang, Kisuk American Chemical Society 2011 Chemistry of materials Vol.23 No.17

<P>Structural characterization of Li<SUB>2–<I>x</I></SUB>MP<SUB>2</SUB>O<SUB>7</SUB> (M = Fe, Co) was carried out using neutron diffraction (ND) and X-ray diffraction (XRD) analyses to elucidate structural information and structural changes during an electrochemical reaction. The crystal system and space group were determined to be monoclinic <I>P</I>2<SUB>1</SUB>/<I>c</I> for both materials with <I>a</I> = 11.0192 (4) Å, <I>b</I> = 9.7488 (3) Å, <I>c</I> = 9.8057 (4) Å, and β = 101.569 (3)° for Li<SUB>2–<I>x</I></SUB>FeP<SUB>2</SUB>O<SUB>7</SUB> and <I>a</I> = 10.9574 (3), <I>b</I> = 9.6921 (3), <I>c</I> = 9.7611 (3), and β = 101.776 (2)° for Li<SUB>2–<I>x</I></SUB>CoP<SUB>2</SUB>O<SUB>7</SUB>. XRD analysis revealed partial occupancy of iron and cobalt in the structures of Li<SUB>2–<I>x</I></SUB>FeP<SUB>2</SUB>O<SUB>7</SUB> and Li<SUB>2–<I>x</I></SUB>CoP<SUB>2</SUB>O<SUB>7</SUB>, respectively. Also, ND identified lithium positions and partial occupancies in five different Li sites of Li<SUB>2–<I>x</I></SUB>MP<SUB>2</SUB>O<SUB>7</SUB> (M = Fe, Co). Further ex situ XRD showed that the charging/discharging of Li<SUB>2–<I>x</I></SUB>FeP<SUB>2</SUB>O<SUB>7</SUB> occurred primarily via a two-phase reaction with a slight solid solution behavior. We also demonstrated for the first time that Li<SUB>2–<I>x</I></SUB>CoP<SUB>2</SUB>O<SUB>7</SUB> electrodes are electrochemically active, with a redox potential of ∼5 V (versus Li).</P><P>We report the detailed structural analysis of Li<SUB>2−<I>x</I></SUB>MP<SUB>2</SUB>O<SUB>7</SUB> (M = Fe, Co) by combined neutron diffraction and X-ray diffraction analyses. XRD analysis revealed the partial occupancies of iron and cobalt in Li<SUB>2−<I>x</I></SUB>MP<SUB>2</SUB>O<SUB>7</SUB>, and ND identified lithium positions and partial occupancies of four different Li sites in the complex crystal structure of Li<SUB>2−<I>x</I></SUB>MP<SUB>2</SUB>O<SUB>7</SUB>. Atomic sites and occupancies were determined by simultaneous Rietveld refinement against XRD and ND patterns, and ex situ XRD analysis revealed that charging/discharging of Li<SUB>2−<I>x</I></SUB>FeP<SUB>2</SUB>O<SUB>7</SUB> occurs primarily via a two-phase reaction. Also, the Li<SUB>2−<I>x</I></SUB>CoP<SUB>2</SUB>O<SUB>7</SUB> electrode is electrochemically active with a redox potential of ∼4.9 V and a high capacity.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2011/cmatex.2011.23.issue-17/cm201305z/production/images/medium/cm-2011-01305z_0003.gif'></P>

New Iron-Based Mixed-Polyanion Cathodes for Lithium and Sodium Rechargeable Batteries: Combined First Principles Calculations and Experimental Study

Kim, Hyungsub,Park, Inchul,Seo, Dong-Hwa,Lee, Seongsu,Kim, Sung-Wook,Kwon, Woo Jun,Park, Young-Uk,Kim, Chul Sung,Jeon, Seokwoo,Kang, Kisuk American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.25

<P>New iron-based mixed-polyanion compounds Li<SUB><I>x</I></SUB>Na<SUB>4–<I>x</I></SUB>Fe<SUB>3</SUB>(PO<SUB>4</SUB>)<SUB>2</SUB>(P<SUB>2</SUB>O<SUB>7</SUB>) (<I>x</I> = 0–3) were synthesized, and their crystal structures were determined. The new compounds contained three-dimensional (3D)sodium/lithium paths supported by P<SUB>2</SUB>O<SUB>7</SUB> pillars in the crystal. First principles calculations identified the complex 3D paths with their activation barriers and revealed them as fast ionic conductors. The reversible electrode operation was found in both Li and Na cells with capacities of one-electron reaction per Fe atom, 140 and 129 mAh g<SUP>–1</SUP>, respectively. The redox potential of each phase was ∼3.4 V (vs Li) for the Li-ion cell and ∼3.2 V (vs Na) for the Na-ion cell. The properties of high power, small volume change, and high thermal stability were also recognized, presenting this new compound as a potential competitor to other iron-based electrodes such as Li<SUB>2</SUB>FeP<SUB>2</SUB>O<SUB>7</SUB>, Li<SUB>2</SUB>FePO<SUB>4</SUB>F, and LiFePO<SUB>4</SUB>.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-25/ja3038646/production/images/medium/ja-2012-038646_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja3038646'>ACS Electronic Supporting Info</A></P>

Spontaneous hybrids of graphene and carbon nanotube arrays at the liquid-gas interface for Li-ion battery anodes

Kim, Hyeri,Kim, Jongsoon,Jeong, Hee-Sung,Kim, Hyungsub,Lee, Hoyeon,Ha, Jae-Min,Choi, Sung-Min,Kim, Tae-Ho,Nah, Yoon-Chae,Shin, Tae Joo,Bang, Joona,Satija, Sushil K.,Koo, Jaseung The Royal Society of Chemistry 2018 Chemical communications Vol.54 No.41

<P>We demonstrate that hybrid structures of graphene and single-walled carbon nanotubes (SWNTs) are precisely controlled at the liquid-gas interface. The functionalized SWNT Langmuir monolayers anchor single-layer graphene nanosheets (GNSs) suspended in water <I>via</I> Coulomb interaction at the interface. This GNS/SWNT hybrid multilayer electrode can be a promising anode material for Li-ion batteries, offering high specific capacity, outstanding power capability, and excellent cyclability.</P>

New 4V-Class and Zero-Strain Cathode Material for Na-Ion Batteries

Kim, Jongsoon,Yoon, Gabin,Lee, Myeong Hwan,Kim, Hyungsub,Lee, Seongsu,Kang, Kisuk American Chemical Society 2017 Chemistry of materials Vol.29 No.18

<P>Here, we introduce Na<SUB>3</SUB>V(PO<SUB>3</SUB>)<SUB>3</SUB>N as a novel 4V-class and zero-strain cathode material for Na-ion batteries. Structural analysis based on a combination of neutron and X-ray diffraction (XRD) reveals that the Na<SUB>3</SUB>V(PO<SUB>3</SUB>)<SUB>3</SUB>N crystal contains three-dimensional channels that are suitable for facile Na diffusion. The Na (de)intercalation is observed to occur at ∼4 V vs Na/Na<SUP>+</SUP> in the Na cell via the V<SUP>3+</SUP>/V<SUP>4+</SUP> redox reaction with ∼67% retention of the initial capacity after over 3000 cycles. The remarkable cycle stability is attributed to the near-zero volume change (∼0.24%) and unique centrosymmetric distortion that occurs during a cycle despite the large ionic size of Na ions for (de)intercalation, as demonstrated by <I>ex situ</I> XRD analysis and first-principles calculations. We also demonstrate that the Na<SUB>3</SUB>V(PO<SUB>3</SUB>)<SUB>3</SUB>N electrode can display outstanding power capability with ∼84% of the theoretical capacity retained at 10C, even though the particle sizes are on the micrometer scale (>5 μm), which is attributed to its intrinsic three-dimensional open-crystal framework. The combination of this high power capability and extraordinary cycle stability makes Na<SUB>3</SUB>V(PO<SUB>3</SUB>)<SUB>3</SUB>N a new potential cathode material for Na-ion batteries.</P> [FIG OMISSION]</BR>

Highly Stable Iron- and Manganese-Based Cathodes for Long-Lasting Sodium Rechargeable Batteries

Kim, Hyungsub,Yoon, Gabin,Park, Inchul,Hong, Jihyun,Park, Kyu-Young,Kim, Jongsoon,Lee, Kug-Seung,Sung, Nark-Eon,Lee, Seongsu,Kang, Kisuk American Chemical Society 2016 Chemistry of materials Vol.28 No.20

<P>The development of long-lasting and low-cost rechargeable batteries lies at the heart of the success of large-scale energy storage systems for various applications. Here, we introduce Fe- and Mn-based Na rechargeable battery cathodes that can stably cycle more than 3000 times. The new cathode is based on the solid-solution phases of Na4MnxFe3-x(PO4)(2)-(P2O7) (x = 1 or 2) that we successfully synthesized for the first time. Electrochemical analysis and ex situ structural investigation reveal that the electrodes operate via a one phase reaction upon charging and discharging with a remarkably low volume change of 2.1% for Na4MnFe2(PO4)(P2O7), which is one of the lowest values among Na battery cathodes reported thus far. With merits including an open framework structure and a small volume change, a stable cycle performance up to 3000 cycles can be achieved at 1C and room temperature, and almost 70% of the capacity at C/20 can be obtained at 20C. We believe that these materials are strong competitors for large-scale Na-ion battery cathodes based on their low costs, long-term cycle stability, and high energy density.</P>

Effect of particle size and amorphous phase on the electrochromic properties of kinetically deposited WO₃ films

Kim, Hyungsub,Choi, Dahyun,Kim, Kwangmin,Chu, Wonshik,Chun, Doo-Man,Lee, Caroline Sunyong Elsevier 2018 Solar energy materials and solar cells Vol.177 No.-

<P><B>Abstract</B></P> <P>The electrochromic (EC) performance of a WO<SUB>3</SUB> film fabricated using a kinetic spray technique (nanoparticle deposition system, NPDS) was examined as a function of the particle size and phase of the WO<SUB>3</SUB> particles. The total transmittance change of the deposited WO<SUB>3</SUB> film containing crystalline nano-sized WO<SUB>3</SUB> particles was 56% at 800nm, which resulted in a large shift in its transmission spectrum after coloring. Moreover, the charge density of the EC film using crystalline nano-sized WO<SUB>3</SUB> particles was 22.06mCcm<SUP>−2</SUP>, which was 2.8 times higher than that of the film composed of crystalline micro-sized WO<SUB>3</SUB> particles (7.97mCcm<SUP>−2</SUP>). Using crystalline nano-sized WO<SUB>3</SUB> particles greatly increased the surface area, increased the number of absorption sites for Li ions inside the film, and thereby improved the charge density and transmittance. The transmittance change of the EC films using dual-phased nano-sized WO<SUB>3</SUB> particles was 64% (at 800nm), which was still higher than that with crystalline nano-sized WO<SUB>3</SUB> particles. The amorphous phase in the dual-phase nano-sized WO<SUB>3</SUB> film provided good diffusion of Li ions; it had a high diffusion coefficient of 1.53 × 10<SUP>−12</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP> that derived from its loosely packed atomic structure. The amorphous region in a heterostructured WO<SUB>3</SUB> film was effective for the fast diffusion of Li ions, while the crystalline nano-sized region in such a film provided a large surface area for an increased number of absorption sites for Li ions. This resulted in a dramatic improvement of the EC performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Different size and phase of WO<SUB>3</SUB> particles were deposited using kinetic spray technique. </LI> <LI> Varying size and phase of the WO<SUB>3</SUB> particles, change charge density. </LI> <LI> Nano WO<SUB>3</SUB> provided more absorption sites for Li ions, which improved EC performance. </LI> <LI> Amorphous/crystalline heterostructured WO<SUB>3</SUB> resulted in loosely packed atomic structure. </LI> <LI> Amorphous/crystalline heterostructured WO<SUB>3</SUB> showed the best EC performance. </LI> </UL> </P>

Anomalous Jahn–Teller behavior in a manganese-based mixed-phosphate cathode for sodium ion batteries

Kim, Hyungsub,Yoon, Gabin,Park, Inchul,Park, Kyu-Young,Lee, Byungju,Kim, Jongsoon,Park, Young-Uk,Jung, Sung-Kyun,Lim, Hee-Dae,Ahn, Docheon,Lee, Seongsu,Kang, Kisuk The Royal Society of Chemistry 2015 ENERGY AND ENVIRONMENTAL SCIENCE Vol.8 No.11

<P>We report a 3.8 V manganese-based mixed-phosphate cathode material for applications in sodium rechargeable batteries; i.e., Na4Mn3(PO4)(2)(P2O7). This material exhibits a largest Mn2+/Mn3+ redox potential of 3.84 V vs. Na+/Na yet reported for a manganese-based cathode, together with the largest energy density of 416 W h kg (1). We describe first-principles calculations and experimental results which show that three-dimensional Na diffusion pathways with low-activation-energy barriers enable the rapid sodium insertion and extraction at various states of charge of the Na4-xMn3(PO4)(2)(P2O7) electrode (where x = 0, 1, 3). Furthermore, we show that the sodium ion mobility in this crystal structure is not decreased by the structural changes induced by Jahn-Teller distortion (Mn3+), in contrast to most manganese-based electrodes, rather it is increased due to distortion, which opens up sodium diffusion channels. This feature stabilizes the material, providing high cycle stability and high power performance for sodium rechargeable batteries. The high voltage, large energy density, cycle stability and the use of low-cost Mn give Na4Mn3(PO4)(2)(P2O7) significant potential for applications as a cathode material for large-scale Na-ion batteries.</P>

Development of R packages: ‘NonCompart’ and ‘ncar’ for noncompartmental analysis (NCA)

Hyungsub Kim,Sungpil Han,조용순,Seok-Kyu Yoon,Kyun-Seop Bae 대한임상약리학회 2018 Translational and Clinical Pharmacology Vol.26 No.1

Noncompartmental analysis (NCA) is a primary analytical approach for pharmacokinetic studies,and its parameters act as decision criteria in bioequivalent studies. Currently, NCA is usuallycarried out by commercial softwares such as WinNonlin®. In this article, we introduce our newlydevelopedtwo R packages, NonCompart (NonCompartmental analysis for pharmacokinetic data)and ncar (NonCompartmental Analysis for pharmacokinetic Report), which can perform NCAand produce complete NCA reports in both pdf and rtf formats. These packages are compatiblewith CDISC (Clinical Data Interchange Standards Consortium) standard as well. We demonstratehow the results of WinNonlin® are reproduced and how NCA reports can be obtained. With these Rpackages, we aimed to help researchers carry out NCA and utilize the output for early stages of drugdevelopment process. These R packages are freely available for download from the CRAN repository.