• 농촌계획
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• 제20권1호
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• pp.63-76
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• 2014

The purpose of this study is to identify effect in how urban garden is run by different operators in Korea, and consequently how it determines the level of community formation among urban garden users. Based on this analysis, the study is intended to present some points as to how to better manage urban garden. The operators are divided into three types: public, public-private partnership and private. The study interviewed each operating entity and surveyed garden users to gauge the extent to which communities are developed. After the ANOVA analysis and Scheffe post-hoc analysis, it was found that the levels of community formation among users of public and public-private partnership urban gardens were similar (so can be grouped together), whereas that of private urban garden users was higher (separated as another group). However, this study found no meaningful differences in the level of community formation among all types of urban garden in a local community. Some key suggestions are made as a result. First, as for the public and public-private partnership types of urban garden, it is necessary to foster leaders to build a community. Next, it is worth noting the potential of public-private partnership in realizing community revival through urban garden. The last suggestion is that, generally, the urban garden has only little influence on community formation in a local area so far, thus more practical consideration needs to be given to enhance the role of urban garden in a local community.

• 정보보호학회논문지
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• 제12권5호
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• pp.37-43
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• 2002

본 논문에서는 기존에 제안된 패스워드 기반의 프로토콜 중 공개키 기반의 프로토콜을 분석하고, 사용자의 서명을 이용한 패스워드 기반의 상호인증 및 세션키 교환 프로토콜인 AKE-ECC를 제안하였다. 제안 프로토콜 AKE-ECC는 사용자와 서버에서 타원곡선의 점의 곱셈 회수가 각각 2회가 실행되며, 서명생성과 인증을 위한 키 쌍(공개키, 비밀키) 생성과 세션키 생성에서 기존의 프로토콜과 달리 키 교환 알고리즘(ECDH)을 이용하여 생성하였다. 또한, 패스워드 기반 프로토콜의 취약점인 dictionary attack 등 알려진 여러 공격으로부터 안전하며, 제안 프로토콜의 안전성은 ECDH, ECDLP를 기반으로 한다.

• 응용통계연구
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• 제24권1호
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• pp.193-206
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• 2011

자녀의 사교육비 지출은 정치, 경제, 사회 등 국민 생활 전반에 걸쳐 막대한 영향을 미치고 그 부작용이 심각하여 한국사회의 중요한 이슈가 되고 있다. 본 논문에서는 통계청에서 수집한 2008년도 사교육비 실태조사 자료 중 일반사교육비 지출과 방과후 프로그램 참가비의 두변수에 대하여 지역, 초 중 고 등 학교급 구분, 가구소득, 학생 성적, 별, 사교육 참가시간 등의 인구동태적 변수들의 영향을 알아보는 다중 선형 회귀분석을 수행 하였다. 분석결과 일반 사교육비 지출과 방과후 프로그램 참가비에 뚜렷한영향을 미치는 요소로는 지역과 학교급구분이고 나머지 변수들은 의미있는 영향력을 보여주지 못하였다. 일반 사교육비 지출에 대한 지역의 영향을 보면, 서울지역>광역시, 중소도시>읍면지역 순으로 지출에 상당한 차이가 있음을 보여주었다. 방과후 참가비에 대한 지역의 영향을 보면 서울지역, 광역시, 중소도시>읍면지역 의 순으로 지출이 많았는데 서울과 기타도시의 차이가 없다는 것이 일반 사교육비의 경우와 다른 특징이다. 학교급 구분에서는 일반사교육비의 경우 일반계 고교생에 대한 지출이 초 중생이나 전문계 고교생에 비하여 약 17% 지출이 더 많았다. 이는 대학입시 위주의 교육 풍토와 사교육 시장이 관련이 있음을 보여준다고 할 수 있다. 방과후 학교 참가비의 경우 일반계고, 초등학교> 전문계고> 중학교 의 순서이다. 초등학생은 사교육비의 부담을 덜기 위해서, 그리고 일반계 고등학생의 경우는 방과후 학교에서 내신에 도움을 주는 프로그램을 제공하기 때문으로 추측할 수 있다.

• ETRI Journal
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• 제36권1호
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• pp.51-61
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• 2014

In the Mobile IPv6 (MIPv6) protocol, a mobile node (MN) is a mobile device with a permanent home address (HoA) on its home link. The MN will acquire a care-of address (CoA) when it roams into a foreign link. It then sends a binding update (BU) message to the home agent (HA) and the correspondent node (CN) to inform them of its current CoA so that future data packets destined for its HoA will be forwarded to the CoA. The BU message, however, is vulnerable to different types of security attacks, such as the man-in-the-middle attack, the session hijacking attack, and the denial-of-service attack. The current security protocols in MIPv6 are not able to effectively protect the BU message against these attacks. The private-key-based BU (PKBU) protocol is proposed in this research to overcome the shortcomings of some existing MIPv6 protocols. PKBU incorporates a method to assert the address ownership of the MN, thus allowing the CN to validate that the MN is not a malicious node. The results obtained show that it addresses the security requirements while being able to check the address ownership of the MN. PKBU also incorporates a method to verify the reachability of the MN.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권3호
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• pp.400-410
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• 2010

In an identity-based threshold broadcast encryption (IDTHBE) scheme, a broadcaster chooses a set of n recipients and a threshold value t, and the plaintext can be recovered only if at least t receivers cooperate. IDTHBE scheme is different from the standard threshold public key encryption schemes, where the set of receivers and the threshold value are decided from the beginning. This kind of scheme has wide applications in ad hoc networks. Previously proposed IDTHBE schemes have ciphertexts which contain at least n elements. In addition, the security of theses schemes relies on the random oracles. In this paper, we introduce two new constructions of IDTHBE for ad hoc networks. Our first scheme achieves S-size private keys while the modified scheme achieves constant size private keys. Both schemes achieve approximately (n-t)-size ciphertexts. Furthermore, we also show that they are provablesecurity under the decision bilinear Diffie-Hellman Exponent (BDHE) assumption in the standard model.

• 한국통신학회논문지
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• 제29권1C호
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• pp.166-174
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• 2004

대리서명은 원서명자가 자신의 서명 권한을 대리 서명자에게 위임하여 대리 서명자가 원서명자를 대신해서 서명을 생성하는 것을 말한다. 대리서명은 원서명자가 위임 정보에 대한 서명을 생성하고 이를 위임자에게 전달하여 위임자가 위임키로서 사용하게 하는 것이다. 본 논문에서는 원서명자와 대리서명자가 기존의 인증서를 발급 받은 환경에서 원서명자가 대리서명자에 대하여 검증자에계 위임정보를 등록하는 프로토콜을 제안한다. 위임내용에 대해 원서명자가 디지털 서명을 하고 검증자는 이에 해당하는 내용을 검증한 후 위임서명자에 대한 권한, 기간 등의 제약사항을 설정하고 허가된 범위 내에서 위임 서명을 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권12호
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• pp.4987-5014
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• 2015

The bilinear pairing, also known as Weil pairing or Tate pairing, is widely used in cryptography and its properties help to construct cryptographic schemes for different applications in which the security of the transmitted data is a major concern. In remote login authentication schemes, there are two major requirements: i) proving the identity of a user and the server for legitimacy without exposing their private keys and ii) freedom for a user to choose and change his password (private key) efficiently. Most of the existing methods based on the bilinear property have some security breaches due to the lack of features and the design issues. In this paper, we develop a new scheme using the bilinear property of an elliptic point and the biometric characteristics. Our method provides many features along with three major goals. a) Checking the correctness of the password before sending the authentication message, which prevents the wastage of communication cost; b) Efficient password change phase in which the user is asked to give a new password after checking the correctness of the current password without involving the server; c) User anonymity - enforcing the suitability of our scheme for applications in which a user does not want to disclose his identity. We use BAN logic to ensure the mutual authentication and session key agreement properties. The paper provides informal security analysis to illustrate that our scheme resists all the security attacks. Furthermore, we use the AVISPA tool for formal security verification of our scheme.

• 환경생물
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• 제32권4호
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• pp.403-412
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• 2014

This article chronicles key shifts in intellectual property regimes in the twentieth century as they related to the commercialization of academic research. The institutionalization and growth of scientific research in the research university in the twentieth century and the increasing awareness of its potential to promote technology innovation and economic growth posited an important question of the ownership of knowledge created in the academic setting, where knowledge was traditionally regarded as a common property among academic researchers. This paper shows the ownership of academic knowledge emerged as a key public policy and legal issue in the latter half of the twentieth century for academic researchers and government officials who pursue the commercialization of academic knowledge for private gain and public benefit. The resulting institutionalization of patent management in the research university and shifts in federal patent policy in turn opened a new legal avenue for the establishment of the private ownership of academic knowledge and the expansion of intellectual property rights in academia, especially in the area of biological and biomedical research. Reflecting upon historical shifts in intellectual property regimes in the twentieth century, this paper suggests recent controversies regarding ownership of biological knowledge and profit sharing in developing counties are linked to critical issues pertinent to the welfare of indigenous population, utilization of new natural resources, and sustainable development for humanity.

• 한국컴퓨터정보학회논문지
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• 제24권8호
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• pp.59-66
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• 2019

As the monetary value of cryptocurrency increases, the security measures for cryptocurrency becomes more important. A limitation of the existing cryptocurrency exchanges is their vulnerability to threats of hacking due to their centralized manner of management. In order to overcome such limitation, blockchain technology is increasingly adopted. The blockchain technology enables decentralization and Peer-to-Peer(P2P) transactions, in which blocks of information are linked in chain topology, and each node participating in the blockchain shares a distributed ledger. In this paper, we propose and implement a mobile electronic wallet that can safely store, send and receive cryptocurrencies. The proposed mobile cryptocurrency wallet connects to the network only when the wallet actively is used. Wallet owner manages his or her private key offline, which is advantageous in terms of security. JavaScript based wallet apps were implemented to respectively run on Android and iOS mobile phones. I demonstrate the process of transferring Ethereum cryptocurrency from an account to another account through Ropsten, a test net for Ethereum. Hardware wallets, such as Ledger Nano S, provide a slightly higher level of security, yet have the disadvantages of added burden of carrying additional physical devices and high costs (about 80$).

• 한국인터넷방송통신학회논문지
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• 제23권6호
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• pp.21-26
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• 2023

최근 디지털 자산으로 불리는 이더리움, 비트코인 등의 암호화폐가 자산으로 빠르게 인식되고 있다. 암호화폐는 실물자산과는 전혀다른 특성을 가지고 있어 신중하고 안전하게 다루어야 하지만 디지털 자산의 단점은 지갑의 개인 키를 아는 사람이라면 누구나 쉽게 해당 디지털 자산을 탈취할 수 있다. 시드카드를 분실하거나 도난 당한경우 또는 작성시 노출된 경우 다른사람이 습득한 시드카드를 이용하여 개인키를 복구하여 지갑을 사용 할 수 있기 때문에 보안에 매우 취약하다. 본 논문에서는 시드카드 작성에 필요한 니모닉 단어 제공시 QR코드를 이용하여 시드카드의 노툴 및 분실, 도난에 대해 안전하게 작성하는 방식을 제안하므로 암호화된 자산을 안전하게 보호하고자 한다.