• Title/Summary/Keyword: SHA1

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A Study on Trends in Cryptography: Virtual Currency Based on Bitcoin and Quantum Computing (암호 화폐에 대한 동향 연구: 비트코인 및 양자 컴퓨팅을 대비하는 가상화폐 기반)

  • Noh, Yoongdoo;Choi, Jiho;Kang, Hongcheol;Yoo, Minjae;Won, Yoojae
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.11a
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    • pp.360-362
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    • 2017
  • 올해 초, 구글(Google)이 SHA-1의 충돌 현상을 입증했다. 이것은 모든 타 암호 알고리즘 역시 안전할 수 없다는 것을 뜻하며, 향후 SHA-256을 사용하는 비트코인도 취약해질 수 있음을 의미한다. 이유인즉슨, 비트코인에서 사용되는 암호 및 해시 알고리즘은 답을 찾기 위해 상당한 시간이 소요되지만, 양자 컴퓨터의 큐비트를 바탕으로 하는 연산처리 능력은 그 시간을 대폭 감소시킬 수 있기 때문이다. 본 논문에서는 이와 같은 양자 컴퓨터가 비트코인에 얼마나 위협적일 수 있는지와 더불어 양자 컴퓨터 출현에 대비하고자 등장한 새로운 암호 화폐인 Byteball 및 QRL코인을 살펴보고자 한다.

Complexation of Cadmium(Ⅱ) with Humic Acids: Effects of pH and Humic Acid Origin

  • Lee, Mee-Hae;Choi, Se-Young;Chung, Kun-Ho;Moon, Hi-Chung
    • Bulletin of the Korean Chemical Society
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    • v.14 no.6
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    • pp.726-732
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    • 1993
  • A comparative study on cadmium(II) complexation with three well characterized humic acids (SHA: soil humic acid from the Okchun Metamorphic Belt; AqHA: aquatic humic acid from Gorleben underground aquifer, Germany; CoHA: commercially available humic acid from the Aldrich Co.) was carried out in 0.1 M $NaClO_4$ at different solution pH(5.0, 5.5, and 6.0) using the ultrafiltration technique. The maximum binding ability (MBA) of the humic acids for cadmium(II) was observed to vary with their origins and solution pH. The results suggest that 1 : 1 complex predominates within the experimental range, and the conditional stability constants were calculated based on the assumption of cooperative binding, yielding log K values that were quite similar (CoHA: 4.17${\pm}$0.08; AqHA: 4.14${\pm}$0.07; SHA: $4.06{\pm} 0.12\;l\;mol^{-1}$ at pH 6.0) irrespective of humic acid origins or pH. By contrast a nonlinear Schatchard plot was obtained, using the cadmium(II) ion selective electrode speciation analysis method, which indicated that humic acid may have two or more classes of binding sites, with $log\;K_1\;and\;log\;K_2$ of 4.73${\pm}$ 0.08 and $3.31{\pm}0.14\;l\;mol^{-1}$ respectively.

2018 Current Health Expenditures and National Health Accounts in Korea (2018년 경상의료비 및 국민보건계정)

  • Jeong, Hyoung-Sun;Shin, Jeong-Woo;Moon, Sung-Woong;Choi, Ji-Sook;Kim, Heenyun
    • Health Policy and Management
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    • v.29 no.2
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    • pp.206-219
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    • 2019
  • This paper aims to demonstrate current health expenditure (CHE) and National Health Accounts of the years 2018 constructed according to the SHA2011, which is a manual for System of Health Accounts (SHA) that was published jointly by the Organization for Economic Cooperation and Development (OECD), Eurostat, and World Health Organization in 2011. Comparison is made with international trends by collecting and analyzing health accounts of OECD member countries. Particularly, scale and trends of the total CHE financing as well as public-private mix are parsed in depth. In the case of private financing, estimation of total expenditures for (revenues by) provider groups (HP) is made from both survey on the benefit coverage rate of National Health Insurance (by National Health Insurance Service) and Economic Census and Service Industry Census (by National Statistical Office); and other pieces of information from Korean Health Panel Study, etc. are supplementarily used to allocate those totals into functional classifications. CHE was 144.4 trillion won in 2018, which accounts for 8.1% of Korea's gross domestic product (GDP). It was a big increase of 12.8 trillion won, or 9.7%, from the previous year. GDP share of Korean CHE has already been close to the average of OECD member countries. Government and compulsory schemes' share (or public share), 59.8% of the CHE in 2018, is much lower than the OECD average of 73.6%. 'Transfers from government domestic revenue' share of total revenue of health financing was 16.9% in Korea, lower than the other social insurance countries. When it comes to 'compulsory contributory health financing schemes,' 'transfers from government domestic revenue' share of 13.5% was again much lower compared to Japan (43.0%) and Belgium (30.1%) with social insurance scheme.

Effects of Rad51 on Survival of A549 Cells

  • Yu, Sha-Sha;Tu, Yi;Xu, Lin-Lin;Tao, Xue-Qin;Xu, Shan;Wang, Shan-Shan;Xiong, Yi-Feng;Mei, Jin-Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.1
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    • pp.175-179
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    • 2015
  • Rad51, a key factor in the homologous recombination pathway for the DNA double-strand break repair, plays a vital role in genesis of non-small-cell lung cancer (NSCLC). In recent years, more and more studies indicate that high expression of Rad51 is of great relevance to resistance of NSCLC to chemotherapeutic agents and ionizing radiation. However, the underlying molecular mechanisms are poorly understood. In this study, we investigated the role of single Rad51 on cell viability in vitro. Our results show that depletion of endogenous Rad51 is sufficient to inhibit the growth of the A549 lung cancer cell line, by accumulating cells in G1 phase and inducing cell death. We conclude that independent Rad51 expression is critical to the survival of A549 cells and can be an independent prognostic factor in NSCLC patients.

Design of FPGA Hardware Accelerator for Information Security System (정보보호 시스템을 위한 FPGA 기반 하드웨어 가속기 설계)

  • Cha, Jeong Woo;Kim, Chang Hoon
    • Journal of Korea Society of Industrial Information Systems
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    • v.18 no.2
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    • pp.1-12
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    • 2013
  • Information Security System is implemented in software, hardware and FPGA device. Implementation of S/W provides high flexibility about various information security algorithm, but it has very vulnerable aspect of speed, power, safety, and performing ASIC is really excellent aspect of speed and power but don't support various security platform because of feature's realization. To improve conflict of these problems, implementation of recent FPGA device is really performed. The goal of this thesis is to design and develop a FPGA hardware accelerator for information security system. It performs as AES, SHA-256 and ECC and is controlled by the Integrated Interface. Furthermore, since the proposed Security Information System can satisfy various requirements and some constraints, it can be applied to numerous information security applications from low-cost applications and high-speed communication systems.

A Study on Korean Man's Head Ornaments in the Joseon Dynasty - Focusing on Pungjam and Kwanja - (조선시대 남자(男子)의 수식(首飾) 연구(II) - 풍잠(風簪)과 관자(貫子)를 중심(中心)으로 -)

  • Chang, Sook-Whan
    • Journal of the Korea Fashion and Costume Design Association
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    • v.12 no.2
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    • pp.1-20
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    • 2010
  • This thesis is about "manggon" that holds down man's top knot hair and its accessaries "pungjam", "kwanja". manggon was seen first time in the mural of Donwhang kae won chon bo during T'ang period (713-756). The "Tu Aek Ra" manggon shown in this mural would be the origin and beginning of maggon's usage. Also the "Sha" that was placed on top of the hair for decoration purpose is believed to be a former form of "manggon" Before the short hair cut was enforced, wearing the "kwan"(head gear) was considered as an impotant etiguette. Thus the head gear was treasured and the manggon which was the most essential piece to cover down the hair before to put on the head gear was regarded as the most important piece. However, since the manggon was tied very tightly around the forehead, manggon caused some sickness. From my private collections of man's head gears and ornament, 121 items were selected and used for analysis and the followings were found: 1. Pungjam was divided into 8 categories according to its shape and a research was made on its unique structural characteristic on each categories. 2. Kwanja's material and design that were used are all in accordance to the historical recordings.

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An Efficient Lookup Mechanism for Unstructured Peer-to-Peer Considering IP Distribution (ISP별 IP분포를 고려한 비구조적 Peer-to-Peer에서의 Lookup 기법)

  • 김홍일;신판섭
    • Journal of the Korea Computer Industry Society
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    • v.4 no.12
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    • pp.873-886
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    • 2003
  • Lookup Is one of important factors for network traffic on peer-to-peer network. Especially, large amount of network resources are required for lookup process in p2p file sharing system that clients use the dynamic If and they import to p2p network in random. In this paper, we employ efficient lookup mechanism which searches lookup with the combined information of ISP key values and the extracted key values from SHA-1 hashing function for shared contents id. The proposed mechanism efficiently searches files on the network because the mechanism processes P2P lookup with consideration the routing information of ISP. We suggest the adapted simulation environment based upon the famous file sharing system of emule P2P and experiment the proposed system.

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Optimized Security Algorithm for IEC 61850 based Power Utility System

  • Yang, Hyo-Sik;Kim, Sang-Sig;Jang, Hyuk-Soo
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.443-450
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    • 2012
  • As power grids are integrated into one big umbrella (i.e., Smart Grid), communication network plays a key role in reliable and stable operation of power grids. For successful operation of smart grid, interoperability and security issues must be resolved. Security means providing network system integrity, authentication, and confidentiality service. For a cyber-attack to a power grid system, which may jeopardize the national security, vulnerability of communication infrastructure has a serious impact on the power grid network. While security aspects of power grid network have been studied much, security mechanisms are rarely adopted in power gird communication network. For security issues, strict timing requirements are defined in IEC 61850 for mission critical messages (i.e., GOOSE). In this paper, we apply security algorithms (i.e., MD-5, SHA-1, and RSA) and measure their processing time and transmission delay of secured mission critical messages. The results show the algorithms satisfying the timing requirements defined in IEC 61850 and we observer the algorithm that is optimal for secure communication of mission critical messages. Numerical analysis shows that SHA-1 is preferable for secure GOOSE message sending.

A Server-Independent Password Authentication Method for Access-Controlled Web Pages Using the SHA-1 Algorithm (SHA-1 방식을 이용한 제한된 웹 페이지에 접근하기 위한 서버 독립적인 패스워드 인정 방안)

  • 하창승;조익성
    • Journal of the Korea Society of Computer and Information
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    • v.6 no.4
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    • pp.146-153
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    • 2001
  • A new password authentication method Is proposed in this paper for the purpose of providing web page authors the convenience in deploying password-protected Web realms at a web server. According to this method. a web realm is mapped to a secret directory at the web server. in which access-controlled web pages are stored. A password is used to construct the name of the secret directory. A javaScript code is embedded in a sign-in web pageoutside the secret directory, which converts the user-entered password into the directory name and forms a complete URL pointing to an access-controlled web page inside the secret directory. Thus, only users knowing the password can compose a valid URL and retrieve the access-controlled web page. Using this method, web page authors can deploy password-protected web realms in a server-independent manner.

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Differential-Linear Type Attacks on Reduced Rounds of SHACAL-2 (축소 라운드 SHACAL-2의 차분-선형 유형 공격)

  • Kim Guil;Kim Jongsung;Hong Seokhie;Lee Sangjin;Lim Jongin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.15 no.1
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    • pp.57-66
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    • 2005
  • SHACAL-2 is a 256-bit block cipher with various key sizes based on the hash function SHA-2. Recently, it was recommended as one of the NESSIE selections. This paper presents differential-linear type attacks on SHACAL-2 with 512-bit keys up to 32 out of its 64 rounds. Our 32-round attack on the 512-bit keys variants is the best efficient attack on this cipher in published literatures.