• Title/Summary/Keyword: MD-2

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Security Analysis of Block Cipher MD-64 Suitable for Wireless Sensor Network Environments (무선 센서 네트워크 환경에 적합한 블록 암호 MD-64에 대한 안전성 분석)

  • Lee, Chang-Hoon
    • Journal of Advanced Navigation Technology
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    • v.15 no.5
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    • pp.865-870
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    • 2011
  • MD-64 is a 64-bit block cipher suitable for the efficient implementation in hardware environments such as WSN. In this paper, we propose a related-key amplified boomerang attack on the full-round MD-64. The attack on the full-round MD-64 requires $2^{45.5}$ related-key chosen plaintexts and $2^{95}$ MD-64 encryptions. This work is the first known cryptanalytic result on MD-64.

Improved Key-Recovery Attacks on HMAC/NMAC-MD4 (HMAC/NMAC-MD4에 대한 향상된 키 복구 공격)

  • Kang, Jin-Keon;Lee, Je-Sang;Sung, Jae-Chul;Hong, Seok-Hie;Ryu, Heui-Su
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.2
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    • pp.63-74
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    • 2009
  • In 2005, Wang et al. discovered devastating collision attacks on the main hash functions from the MD4 family. After the discovery of Wang, many analysis results on the security of existing hash-based cryptographic schemes are presented. At CRYPTO'07, Fouque, Leurent and Nguyen presented full key-recovery attacks on HMAC/NMAC-MD4 and NMAC-MD5[4]. Such attacks are based on collision attacks on the underlying hash function, and the most expensive stage is the recovery of the outer key. At EUROCRYPT'08, Wang, Ohta and Kunihiro presented improved outer key recovery attack on HMAC/NMAC-MD4, by using a new near collision path with a high probability[2]. This improves the complexity of the full key-recovery attack on HMAC/NMAC-MD4 which proposed by Fouque, Leurent and Nguyen at CRYPTO'07: The MAC queries decreases from $2^{88}$ to $2^{72}$, and the number of MD4 computations decreases from $2^{95}$ to $2^{77}$. In this paper, we propose improved outer key-recovery attack on HMAC/NMAC-MD4 with $2^{77.1246}$ MAC queries and $2^{37}$ MD4 computations, by using divide and conquer paradigm.

Estimation of storability for Korean apples (Malus domestica) using Md-ACS1 and Md-ACO1 DNA marker (Md-ACS1 및 Md-ACO1 분자표지를 이용한 국내육성사과의 저장성 예측)

  • Kwon, Young Soon;Kwon, Soon-Il;Kim, Seon Ae;Kweon, Hun-Joong;Yoo, Jingi;Ryu, Seulgi;Kang, In-Kyu;Kim, Jeong-Hee
    • Food Science and Preservation
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    • v.24 no.7
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    • pp.891-897
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    • 2017
  • Apple (Malus domestica) is a climacteric fruit because of its high respiration and ethylene production. Ethylene affects the fruit by decreasing its quality and storability. Md-ACS1 and Md-ACO1 genes are involved in ethylene biosynthesis in apple; the Md-ACS1-2 and Md-ACO1-1 alleles are associated with low ethylene production. We conducted an analysis to study Md-ACS1 and Md-ACO1, and to examine ethylene production and softening rate of fruit at room temperature ($20^{\circ}C$) storage in 'Fuji (FJ)', 'Golden Supreme (GS)', and 5 cultivars of Korean apples ('RubyS (RS)', 'Hongro (HR)', 'Arisoo (AS)', 'Summer King (SK)', 'Greenball (GB)'). The result showed that an increase in the number of the alleles (ACS1-2, ACO1-1) decreased the ethylene production and softening rate. The presence of ACS1-1/1, ACO1-1/2 was confirmed in GS and the highest ethylene production and softening rate was observed. Ethylene production and softening rate of SK and GB expressing ACS1-1/2, ACO1-1/2 were higher than that of HR and AS, expressing ACS1-2/2, ACO1-1/2, but lower than GS. FJ with ACS1-2/2, ACO1-1/1 showed the lowest ethylene production and softening rate among all cultivars except RS. The Md-ACS1 and Md-ACO1 DNA markers could potentially be used to estimate storability and applied in marker assisted selection the improve the efficiency of apple breeding.

Multi-Device-to-Multi-Device Communication for Efficient Contents Distribution on Board the Ship (선박 내 효과적인 콘텐츠 분배를 위한 다중 단말 간 직접통신)

  • You, Dongho;Kwon, Eunjeong;Kim, Dong Ho;Lee, Seong Ro
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.8
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    • pp.681-687
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    • 2014
  • Internet traffic is rapidly increasing due to the spread of personal smart devices. It causes serious burden on base stations and access points which are installed in buildings, buses, trains, and ships. We consider a communication scenario aboard a cruise ship and propose efficient contents distribution schemes to alleviate the burden of access points with multi-device-to-multi-device(MD2MD) communication. The proposed transmission method is based on the hybrid STBC-SM scheme. We compare the error performance of MD2MD communication system on the cruise ship using space-time block coding (STBC) scheme, spatial multiplexing (SM) scheme. The proposed MD2MD communication system is expected to adopt in the ship-area-network (SAN) with efficient contents distribution and reliable communication.

Kinetics of Binding of LPS to Recombinant CD14, TLR4, and MD-2 Proteins

  • Shin, Han Jae;Lee, Hayyoung;Park, Jong Dae;Hyun, Hak Chul;Sohn, Hyung Ok;Lee, Dong Wook;Kim, Young Sang
    • Molecules and Cells
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    • v.24 no.1
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    • pp.119-124
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    • 2007
  • TLR4 together with CD14 and MD-2 forms a pattern recognition receptor that plays an initiating role in the innate immune response to Gram-negative bacteria. Here, we employed the surface plasmon resonance technique to investigate the kinetics of binding of LPS to recombinant CD14, MD-2 and TLR4 proteins produced in insect cells. The dissociation constants ($K_D$) of LPS for immobilized CD14 and MD-2 were $8.7{\mu}m$, and $2.3{\mu}m$, respectively. The association rate constant ($K_{on}$) of LPS for MD-2 was $5.61{\times}10^3M^{-1}S^{-1}$, and the dissociation rate constant ($K_{off}$) was $1.28{\times}10^2S^{-1}$, revealing slow association and fast dissociation with an affinity constant $K_D$ of $2.33{\times}10^6M$ at $25^{\circ}C$. These affinities are consistent with the current view that CD14 conveys LPS to the TLR4/MD-2 complex.

Dynamic lipopolysaccharide transfer cascade to TLR4/MD2 complex via LBP and CD14

  • Kim, Soo Jin;Kim, Ho Min
    • BMB Reports
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    • v.50 no.2
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    • pp.55-57
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    • 2017
  • Toll-like receptor 4 (TLR4) together with MD2, one of the key pattern recognition receptors for a pathogen-associated molecular pattern, activates innate immunity by recognizing lipopolysaccharide (LPS) of Gram-negative bacteria. Although LBP and CD14 catalyze LPS transfer to the TLR4/MD2 complex, the detail mechanisms underlying this dynamic LPS transfer remain elusive. Using negative-stain electron microscopy, we visualized the dynamic intermediate complexes during LPS transfer-LBP/LPS micelles and ternary CD14/LBP/LPS micelle complexes. We also reconstituted the entire cascade of LPS transfer to TLR4/MD2 in a total internal reflection fluorescence (TIRF) microscope for a single molecule fluorescence analysis. These analyses reveal longitudinal LBP binding to the surface of LPS micelles and multi-round binding/unbinding of CD14 to single LBP/LPS micelles via key charged residues on LBP and CD14. Finally, we reveal that a single LPS molecule bound to CD14 is transferred to TLR4/MD2 in a TLR4-dependent manner. These discoveries, which clarify the molecular mechanism of dynamic LPS transfer to TLR4/MD2 via LBP and CD14, provide novel insights into the initiation of innate immune responses.

Clinical Features of Complicated Meckel's Diverticulum Requiring Operation in Children (소아에서 수술을 요한 멕켈게실의 임상상)

  • Lee, Seong-Cheol;Mok, Woo-Kyun;Seo, Jung-Min;Jung, Sung-Eun;Park, Kwi-Won;Kim, Woo-Ki
    • Advances in pediatric surgery
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    • v.1 no.1
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    • pp.33-39
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    • 1995
  • The incidence of Meckel's diverticulum(MD) in general population has been assessed as 2 percent. The major complications of MD are bleeding, perforation, and intestinal obstruction. In spite that the complication rate of Meckel's diverticulum is relatively high(about 4.2% during a lifetime), the preoperative diagnostic rate of complicated MD is very low. Authors investigated the clinical characteristics of complicated MD to improve the diagnostic rate. 16 patients with complicated Meckel's diverticulum who were operated upon at the Department of Pediatric Surgery, Seoul National University Children's Hospital from June 1985 to December 1993 were reviewed. Among the 16 patients with complicated MD, 12 patients(75%) were under 2 year-old and male were predominant(88%). The most common complication was bleeding patients with bleeding MD (8 cases) were diagnosed preoperatively as MD. 8 patients with other complications(perforation : 4 cases, obstruction : 4 cases) could not be suspected as complicated MD except one patient who had previous history of melena. These patients were diagnosed after exploratory laparotomy under the various impression other than MD. Among 12 patients with ulcer related complications such as bleeding and perforation, heterotopic gastric mucosa was found in 11 patients. In conclusion, in any children with unexplained acute abdomen, especially under 2 years old, complicated MD must be included in differential diagnosis. In children with obscure lower gastrointestinal bleeding, $^{99m}Tc$-pertechnetate scintigraphy is a useful diagnostic tool to rule out bleeding MD.

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A Study on Quality Characteristics of Dangmyon(starch vermicelli) added with Mulberry Leaves Powder (뽕잎분말을 첨가한 당면의 품질특성에 관한 연구)

  • Jeon, Seo-Young;Lee, Young-Sook;Rho, Jeong-Ok
    • Korean Journal of Human Ecology
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    • v.24 no.3
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    • pp.437-449
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    • 2015
  • The purpose of this study was to investigate the quality characteristics of Dangmyon(starch vermicelli) prepared with mulberry leaves powder. Mulberry leaves powder was added in ratios (w/w) of 0% (CON), 0.5% (MD1), 1.0% (MD2), 1.5% (MD3). and 2.0%(MD4), and then proximate compositions, physicochemical properties, RVA, SEM, texture and sensory evaluations of the Dangmyon were measured. MD1~MD4 samples showed higher contents of moisture, crude lipid, crude protein and crude ash as well as pH compared to control (p<0.001). In terms of color, lightness (L), yellowness (b), and redness (a) decreased as the mulberry leaves powder increased. The results of RVA properties analysis on all samples showed that control had the highest. With regard to the texture of Dangmyon samples, the scores of hardness, adhesiceness, gumminess, chewiness, resilience of CON was significantly higher than the samples MD1~MD4 (p<0.001), but the scores of springiness, cohesiveness was not significantly among samples. The result of observation on the cross section of Dangmyon added with mulberry leaves powder showed that number, size of cavity more increase compared to the control. In sensory evaluation, the scores of appearance, flavor, taste and overall preference for MD3 were significantly higher than the samples (CON, MD1, MD2, and MD4). From the findings, this study suggests that 1.5% addition of mulberry leaves powder was effective for preparation of Dangmyon in the aspects of the consumer acceptability.

The Prospect of Membrane Distillation (Membrane Distillation의 전망)

  • 조한욱;신우철
    • Membrane Journal
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    • v.7 no.2
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    • pp.57-64
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    • 1997
  • Membrane Distillation(MD) is reviewed as an application to new separation technology. Hydrophobic membrane which has been used to microfiltration is feasible material for MD process. MD has perfect selectivity under moderate temperature and is promised to simplify typical water treatment process. The principle of MD separation is phase transition by vapor-liquid interface at the pore of membrane surface. Feed and permeate temperature, composition, membrane wetting, heat and mass transfer phenomena affect the selectivity and flux of MD.

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Anti-Obesity Effect of Enterococcus faecalis MD366 isolated from Raw Milk in Diet-Induced Obese Mice (원유에서 분리한 Enterococcus faecalis MD366가 고지방식이를 급여한 마우스의 비만 억제에 미치는 영향)

  • Park, Sun-Young;Cho, Seong-A;Han, Noo-Ri;Seong, Ki-Seung;Lim, Sang-Dong
    • Journal of Dairy Science and Biotechnology
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    • v.32 no.2
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    • pp.163-167
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    • 2014
  • This study aimed to investigate the anti-obesity effects of Enterococcus faecalis MD366, isolated from raw milk, in diet-induced obese mice. To examine the effect, male C57BL/6J mice were fed for six weeks on three different diets, i.e., a normal diet and orally administrated saline solution (ND), a high-fat diet and orally administrated saline solution (HFD), and a high-fat diet and orally administrated E. faecalis MD366 ($10^9CFU/day$) in saline solution (HFD+MD366). After six weeks, the rate of increase in body weight was 18.1% lower in the HFD+MD366 group compared to that in the HFD group. In addition, the weight of epididymal fat pad in the HFD+MD366 group was lower than that in the HFD group. The average levels of triglycerides, total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) were slightly reduced in the HFD+MD366 group compared to those in the HFD group. However, there were no significant differences between the groups. Measuring the adipocytes revealed that the percentage of adipocytes with a size of $2,000{\mu}m^2$ was higher than the percentages of other size classes in ND and HFD+MD366 groups, while the percentage of adipocytes larger than $5,000{\mu}m^2$ was highest in the HFD group. The mean adipocyte size in the HFD+MD366 group was smaller than that in the HFD group.

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