• Title/Summary/Keyword: private key

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Lessons from British Port Privatisation

  • Kim, Jin-Hwan
    • Journal of Distribution Science
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    • v.13 no.2
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    • pp.5-13
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    • 2015
  • Purpose - In recent years, concerns over privatization have been growing in some public sectors. Privatization in Britain offers lessons for those who have intended to privatize their industry, and in particular, the port industry. Therefore, it is useful for researchers to examine British port privatization in detail, particularly the implications of UK port privatization. Research design, data, and methodology - After reviewing the historical development of the UK port industry, the important factors determining the success of the British port privatization process were identified. The interpretations could be lessons for some other country to consider port privatization in near future. Results - The key factors in relation to port privatization are first, regulation; second, ownership; and third, utilities and operations, which includes autonomy, efficiency, and competitiveness. In addition, the UK port management system is a pure private port system, which has been successful. Conclusions - In Britain, after deciding to privatize the erstwhile public ports, they were fully privatized, focusing on the aforesaid key factors. This offers important lessons for the privatization of other ports in the world.

Certificate Issuing Protocol Supporting WAKE-KR (WAKE-KR을 지원하는 인증서 발행 프로토콜)

  • 이용호;이임영
    • Journal of Korea Multimedia Society
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    • v.6 no.2
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    • pp.288-300
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    • 2003
  • As the importance of information security gets recognized seriously, ciphers technology gets used more. Particularly, since public key ciphers are easier to control the key than symmetric key ciphers and also digital signature is easily implemented, public key ciphers are increased used. Nowadays, public key infrastructure is established and operated to use efficiently and securely the public key ciphers. In the public key infrastructure, the user registers at the certificate authority to generate the private key and public key pair and the certificate authority issues the certificate on the public key generated. Through this certificate, key establishment between users is implemented and encryption communication becomes possible. But, control function of session key established in the public key infrastructure is not provided. In this thesis, the certificate issuing protocol to support the key recovery of the session key established during the wireless authentication and key establishment is proposed.

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Construction of Efficient Distributed Authentication Server without Additional Key Management (부가적인 키관리를 필요로 하지 않는 효율적인 분산 인증서버의 구축)

  • Hong, Seong-Min;Yoon, Hyun-Soo;Lee, Seung-Won;Park, Yon-Su;Cho, Yoo-Kun
    • Journal of KIISE:Information Networking
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    • v.27 no.2
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    • pp.175-186
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    • 2000
  • Over the years, the extensive use of networks and distributed systems has increased the need for authentication and digital signatures. Inperforming authentication on a massive scale, authentication servers that use multiple workstations or PCs are more economical than servers that use one inicomputer or mainframe. However, the establishment of authentication servers with multiple platforms can cause some security problems and increases the cost of key management because all platforms within the server must have the private key of the authentication server. We propose a scheme which can solve these problems. The proposed scheme can establish a strong authentication server with no additional key management and improve the performance of the authentication server up to 13 times.

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A Study on Digital Watermarking of MPEG Coded Video Using Wavelet Transform (웨이블릿 변환를 이용한 MPEG 디지털동영상 워터마킹에 관한 연구)

  • Lee, Hak-Chan;Jo, Cheol-Hun;Song, Jung-Won
    • The KIPS Transactions:PartB
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    • v.8B no.5
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    • pp.579-586
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    • 2001
  • Digital watermarking is to embed imperceptible mark into image, video, audio, and text data to prevent the illegal copy of multimedia data. arbitrary modification, and also illegal sales of the copies without agreement of copyright ownership. In this paper, we study for the embedding and extraction of watermark key using wavelet in the luminance signal in order to implement the system to protect the copyright for image MPEG. First, the original image is analyzed into frequency domain by discrete wavelet transform. The RSA(Rivest, Shamir, Aldeman) public key of the coded target is RUN parameter of VLD(variable length coding). Because the high relationship among the adjacent RUN parameters effect the whole image, it prevents non-authorizer not to possess private key from behaving illegally. The Results show that the proposed method provides better moving picture and the distortion more key of insert than direct coded method on low-frequency domain based DCT.

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Disparities in High-cost Outpatient Imaging Test Utilization between Private Health Insurance Subscribers and Non-subscribers: Changes Following the National Health Insurance Benefit Expansion Policy (민간의료보험 가입자와 미가입자 간 외래 고가영상검사 이용의 격차: 건강보험 보장성 강화 정책에 따른 변화)

  • Yukyung Shin;Young Kyung Do
    • Health Policy and Management
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    • v.33 no.3
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    • pp.325-337
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    • 2023
  • Background: While there are many studies estimating the effects of private health insurance on various types of health care utilization, few have examined how such effects change in conjunction with important policy reforms in national health insurance (NHI). This study examined how the effect of private health insurance (supplemental and fixed cash benefit) on high-cost outpatient imaging test utilization changed following the expansion of magnetic resonance imaging (MRI) coverage in 2018, which is a key example of the NHI benefit expansion policy in recent years. Methods: Data from the 2017 and 2019 Korea Health Panel Survey, which contained information about healthcare utilization before and after the expansion of MRI coverage in 2018, were used. The incremental effect of private health insurance on high-cost outpatient imaging test utilization for each period were quantified and compared, with special attention given to the type of private health insurance. Results: While people with supplemental private health insurance were more likely to use high-cost outpatient imaging tests than those without, both before and after the expansion of MRI coverage, the incremental effect increased from 1.6% points in 2017 to 2.5% points in 2019. Conclusion: Benefit expansion in NHI does not necessarily reduce disparities in the use of health care between private health insurance subscribers and non-subscribers. The results of our study also suggest that the path through which private health insurance affects healthcare utilization may not be limited to the price mechanism alone but can be more complex.

The Performance and Implication of A Market-oriented Health Care System in United States (미국 시장지향 의료체계의 성과와 시사점)

  • Lee, Key-Hyo
    • Korea Journal of Hospital Management
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    • v.9 no.1
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    • pp.1-21
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    • 2004
  • The United States has a unique health care system, which is unlikely any other health care systems in the world. The major part of basic functional components of the system -financing, insurance, delivery, and payment- is in private hands. A market-oriented economy invites the participation of numerous private entities that are interested in carrying out the key functions of health systems. Due to this central feature, U.S.health care is not delivered through a network of interrelated components designed to work together coherently. For lack of standardization, the various components of the system fit together only loosely. The involvement of numerous players in the key functions leads to duplication, overlap, inadequacy, inconsistency, and waste, which add to the complexity and also make the system inefficient. Hence, cost containment remains an elusive goals. Moreover, the system falls short of delivering equitable services to all americans, though consumption of health care services is the largest in the world. On the other hand, United States leads the world in the latest and the best in medical technology, medical training, and research. It offers some of the most sophisticated institutions, products, and processes of health care delivery. This article discuss the characteristic features of the U.S. health care system. and its performance, trying to seek its implication on Korean health care system.

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A Physical Combined Attack and its Countermeasure on BNP Exponentiation Algorithm (BNP 멱승 알고리듬에 대한 물리적인 조합 공격 및 대응책)

  • Kim, Hyung-Dong;Ha, Jae-Cheol
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.23 no.4
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    • pp.585-591
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    • 2013
  • Recently, the combined attack which is a combination of side channel analysis and fault attack has been developed to extract the secret key during the cryptographic processes using a security device. Unfortunately, an attacker can find the private key of RSA cryptosystem through one time fault injection and power signal analysis. In this paper, we diagnosed SPA/FA resistant BNP(Boscher, Naciri, and Prouff) exponentiation algorithm as having threats to a similar combined attack. And we proposed a simple countermeasure to resist against this combined attack by randomizing the private key using error infective method.

Signcryption Schemes with Forward Secrecy (Forward Secrecy를 제공하는 Signcryption 기법들)

  • 정희윤;이동훈;임종인
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.11 no.5
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    • pp.43-52
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    • 2001
  • Y. Zheng introduced a new type of cryptograghic primitive as \"signcryption\", which combines a function of digital signature scheme with a symmetric key encryption algorithm. Signcryption doesn\`t only provide authenticity and confidentiality in a single step, but also give more efficient computation than the traditional \"signature-then-encryption\". And C. Gamage proposed a proxy-signcryption that efficiently combines a proxy signature with the signcryption. But, in the proposed signcryption schemes, one who obtains the sender\`s private key can recover the original message of a signcrypted text. That is, forward secrecy is not offered by the signcryption scheme with respect to the sender\`s private key. In this paper, we will propose a modified signcryption of Zheng\`s signcryption and a variant of proxy-signcryption with forward secrecy.ith forward secrecy.

A fault attack on elliptic curve scalar multiplication based on Euclidean Addition Chain (Euclidean Addition Chain을 사용하는 타원곡선 스칼라 곱셈 연산에 대한 오류 주입 공격)

  • Lee, Soo Jeong;Cho, Sung Min;Hong, Seokhie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.5
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    • pp.1019-1025
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    • 2012
  • Fault attacks manipulate the computation of an algorithm and get information about the private key from the erroneous result. It is the most powerful attack for the cryptographic device. Currently, the research on error detection methods and fault attacks have been studied actively. S. Pontarelli et al. introduced an error detection method in 2009. It can detect an error that occurs during Elliptic Curve Scalar Multiplication (ECSM). In this paper, we present a new fault attack. Our attack can avoid the error detection method introduced by S. Pontarelli et al. We inject a bit flip error in the Euclidean Addition Chain (EAC) on the private key in ECSM and retrieve the private key.

Non-Profiling Analysis Attacks on PQC Standardization Algorithm CRYSTALS-KYBER and Countermeasures (PQC 표준화 알고리즘 CRYSTALS-KYBER에 대한 비프로파일링 분석 공격 및 대응 방안)

  • Jang, Sechang;Ha, Jaecheol
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.32 no.6
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    • pp.1045-1057
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    • 2022
  • Recently, the National Institute of Standards and Technology (NIST) announced four cryptographic algorithms as a standard candidates of Post-Quantum Cryptography (PQC). In this paper, we show that private key can be exposed by a non-profiling-based power analysis attack such as Correlation Power Analysis (CPA) and Differential Deep Learning Analysis (DDLA) on CRYSTALS-KYBER algorithm, which is decided as a standard in the PKE/KEM field. As a result of experiments, it was successful in recovering the linear polynomial coefficient of the private key. Furthermore, the private key can be sufficiently recovered with a 13.0 Normalized Maximum Margin (NMM) value when Hamming Weight of intermediate values is used as a label in DDLA. In addition, these non-profiling attacks can be prevented by applying countermeasures that randomly divides the ciphertext during the decryption process and randomizes the starting point of the coefficient-wise multiplication operation.