• KSII Transactions on Internet and Information Systems (TIIS)
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• v.2 no.6
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• pp.312-332
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• 2008

Password-based authentication key exchange (PAKE) protocols in the literature typically assume a password that is shared between a client and a server. PAKE has been applied in various environments, especially in the “client-server” applications of remotely accessed systems, such as e-banking. With the rapid developments in modern communication environments, such as ad-hoc networks and ubiquitous computing, it is customary to construct a secure peer-to-peer channel, which is quite a different paradigm from existing paradigms. In such a peer-to-peer channel, it would be much more common for users to not share a password with others. In this paper, we consider password-based authentication key exchange in the three-party setting, where two users do not share a password between themselves but only with one server. The users make a session-key by using their different passwords with the help of the server. We propose an efficient password-based authentication key exchange protocol with different passwords that achieves forward secrecy in the standard model. The protocol requires parties to only memorize human-memorable passwords; all other information that is necessary to run the protocol is made public. The protocol is also light-weighted, i.e., it requires only three rounds and four modular exponentiations per user. In fact, this amount of computation and the number of rounds are comparable to the most efficient password-based authentication key exchange protocol in the random-oracle model. The dispensation of random oracles in the protocol does not require the security of any expensive signature schemes or zero-knowlegde proofs.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1933-1942
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• 2008

Over the years, the Social Republic of Vietnam has demonstrated its high annual growth rate over 8%. In order to secure its sustainable economic growth, its has also demonstrated its sharp concerns on building up core infrastructures by luring foreign investments on a large scale, which would underpin the nation's economic propulsion. Among others, transport infrastructures and networks centering on railway systems are obviously seen as the most urgent to be built to continue its growth. Seoul Metro recently took a significant step forward in Vietnam to launch railway business by executing its export project of 6 units of metro cars to Hanoi as on July 10, 2008. Those 6 cars are scheduled to be put on the tracks linking Yen Bian, Hanoi with Ha Long, for demonstrative running, around October, 2008, carrying tourists on that 163kms of the National Railway line serving the region. A successful running on the track will duly entail further export of additional 54 units of Seoul Metro cars to Vietnam. In this thesis, description will be noted on the reuse and economic value of the Seoul Metro's de-commissioned metro cars, reflecting on the current urban railway law at home regulating the service life of rolling stocks domestically. This thesis will also study the points at issue, and the recommendable future orientation of the Vietnam railway business project.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.4
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• pp.163-181
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• 2004

Group key agreement protocols are designed to solve the fundamental problem of securely establishing a session key among a group of parties communicating over a public channel. Although a number of protocols have been proposed to solve this problem over the years, they are not well suited for a high-delay wide area network; their communication overhead is significant in terms of the number of communication rounds or the number of exchanged messages, both of which are recognized as the dominant factors that slow down group key agreement over a networking environment with high communication latency. In this paper we present a communication-efficient group key agreement protocol and prove its security in the random oracle model under the factoring assumption. The proposed protocol provides perfect forward secrecy and requires only a constant number of communication rounds for my of group rekeying operations, while achieving optimal message complexity.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.93-101
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• 2023

In this paper, as a result of analyzing the TMIS authentication protocol using ECC and biometric information proposed by Chen-Chen in 2023, there were security problems such as user impersonation attack, man-in-the-middle attack, and user anonymity. Therefore, this paper proposes an improved authentication protocol that provides user anonymity to solve these problems. As a result of analyzing the security of the protocol proposed in this paper, it was analyzed to be secure for various attacks such as offline password guessing attack, user impersonation attack, smart-card loss attack, insider attack, perfect forward attack. It has also been shown to provided user privacy by guaranteeing user anonymity and untraceability, which must be guaranteed in TMIS. In addition, there was no significant increase in computational complexity, so the efficiency of execution time was achieved. Therefore, the proposed protocol in this paper is a suitable user authentication protocol for TMIS.

• The Journal of Bigdata
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• v.8 no.2
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• pp.141-148
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• 2023

Recent advancements in the integration of satellite technology and the Internet of Things (IoT) have led to the development of a sophisticated network ecosystem, capable of generating and utilizing vast amounts of big data across various sectors. However, this integrated network faces significant security challenges, primarily due to constraints like limited latency, low power requirements, and the incorporation of diverse heterogeneous devices. Addressing these security concerns, this paper explores the construction of a satellite-IoT network through the application of Software Defined Networking (SDN). While SDN offers numerous benefits, it also inherits certain inherent security vulnerabilities. To mitigate these issues, we propose a novel approach that incorporates blockchain technology within the SDN framework. This blockchain-based SDN environment enhances security through a distributed controller system, which also facilitates the authentication of IoT terminals and nodes. Our paper details the implementation plan for this system and discusses its validation through a series of tests. Looking forward, we aim to expand our research to include the convergence of artificial intelligence with satellite-IoT devices, exploring new avenues for leveraging the potential of big data in this context.

• (The) Research of the performance art and culture
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• no.41
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• pp.5-38
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• 2020

The current state of performance halls in South Korea is closely related to the performance art and culture of the nation as the culture of putting on and enjoying a performance is deeply rooted in public culture and arts halls representing each area at the local government level. Today, public culture and arts halls have multiple management purposes, and the subjects of their management are in the public domain including the central and local governments or investment and donation foundations in overwhelming cases. Public culture and arts halls thus have close correlations with the institutional aspect of cultural policies as the objects of culture and art policies at the central and local government level. The full-blown era of public culture and arts halls opened up in the 1980s~1990s, during which multi-purpose performance halls of a similar structure became universal around the nation. Public culture and arts halls of the uniform shape were distributed around the nation with no premise of genre characteristics or local environments for arts, and this was attributed to the cultural policies of the military regime. The Park Chung-hee regime proclaimed Yusin that was beyond the Constitution and enacted the Culture and Arts Promotion Act(September, 1972), which was the first culture and arts act in the nation. Based on the act, a five-year plan for the promotion of culture and arts(1973) was made and led to the construction of cultural facilities. "Public culture and arts" halls or "culture" halls were built to serve multiple purposes around the nation because the Culture and Arts Promotion Act, which is called the starting point of the nation's legal system for culture and arts, defined "culture and arts" as "matters regarding literature, art, music, entertainment, and publications." The definition became a ground for the current "multi-purpose" concept. The organization of Ministry of Culture and Public Information set up a culture and administration system to state its supervision of "culture and arts" and distinguish popular culture from the promotion of arts. During the period, former President Park exhibited his perception of "culture=arts=culture and arts" in his speeches. Arts belonged to the category of culture, but it was considered as "culture and arts." There was no department devoted to arts policies when the act was enacted with a broad scope of culture accepted. This ambiguity worked as a mechanism to mobilize arts in ideological utilizations as a policy. Against this backdrop, the Sejong Center for the Performing Arts, a multi-purpose performance hall, was established in 1978 based on the Culture and Arts Promotion Act under the supervision of Ministry of Culture and Public Information. There were, however, conflicts of value over the issue of accepting the popular music among the "culture and arts = multiple purposes" of the system, "culture ≠ arts" of the cultural organization that pushed forward its establishment, and "culture and arts = arts" perceived by the powerful class. The new military regime seized power after Coup d'état of December 12, 1979 and failed at its culture policy of bringing the resistance force within the system. It tried to differentiate itself from the Park regime by converting the perception into "expansion of opportunities for the people to enjoy culture" to gain people's supports both from the side of resistance and that of support. For the Chun Doo-hwan regime, differentiating itself from the previous regime was to secure legitimacy. Expansion of opportunities to enjoy culture was pushed forward at the level of national distribution. This approach thus failed to settle down as a long-term policy of arts development, and the military regime tried to secure its legitimacy through the symbolism of hardware. During the period, the institutional ground for public culture and arts halls was based on the definition of "culture and arts" in the Culture and Arts Promotion Act enacted under the Yusin system of the Park regime. The "multi-purpose" concept, which was the management goal of public performance halls, was born based on this. In this context of the times, proscenium performance halls of a similar structure and public culture and arts halls with a similar management goal were established around the nation, leading to today's performance art and culture in the nation.

• Strategy21
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• s.31
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• pp.142-163
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• 2013

Ieodo is a submerged rock within a Korea's Exclusive Economic Zone(EEZ) in the East China Sea with its most shallow part about 4.6m below the sea level which has no specific rights for the EEZ delimitation. The United Nations Convention on the Law of the Sea (UNCLOS) stipulates that any coastal state has the rights to claim an EEZ that stretches up to 200 nautical miles from its shore, except where there is an overlap with a neighboring country's claims. Korea claims that Ieodo is within its EEZ as it sits on the Korean side of the equidistant line and the reef is located on the Korea section of the continental shelf. China does not recognize Korea's application of the equidistance principle and insists that Ieodo lies on its continental shelf. According to UNCLOS, Ieodo is located in international waters, rather than one country's EEZ as the two countries have failed to reach a final agreement over the delimitation of the maritime border. This study seeks to understand the evolution of the People's Liberation Army Navy(PLAN) strategy as main obstacles for the EEZ delimitation between Korea and China. PLAN's Strategy evolves from "coastal defense" to "offshore defence", since the late 1980s from a "coastal defence" strategy to an "offshore defence" strategy which would extend the perimeter of defence to between 200 nm and 400 nm from the coast. China's economic power has increased It's dependence on open trade routes for energy supplies and for its own imports and exports. China want secure Sea Lane. PLAN's "offshore defence" strategy combines the concept of active defence with the deployment of its military forces beyond its borders. China's navy try to forward base its units and to achieve an ocean going capability. China's navy expects to have a 'Blue Water' capability by 2050. China insists that coastal states do have a right under UNCLOS to regulate the activities of foreign military forces in their EEZs. China protests several times against US military forces operating within It's EEZ. The U.S. position is that EEZs should be consistent with customary international law of the sea, as reflected in UNCLOS. U.S. has a national interest in the preservation of freedom of navigation as recognized in customary international law of the sea and reflected in UNCLOS. U.S. insists that coastal states under UNCLOS do not have the right to regulate foreign military activities in their EEZs. To be consistent with its demand that the U.S. cease performing military operations in china's EEZ, China would not be able to undertake any military operations in the waters of South Korea's EEZ. As such, to preserve its own security interests, China prefers a status quo policy and used strategic ambiguity on the Ieodo issue. PLAN's strategy of coastal defence has been transformed into offensive defence, Korea's EEZ can be a serious limitation to PLAN's operational plan of activities. Considering China'a view of EEZs, China do not want make EEZ delimitation agreement between Korea and China. China argues that the overlapping areas between EEZs should be handled through negotiations and neither side can take unilateral actions before an agreement is reached. China would prefer Ieodo sea zone as a international waters, rather than one country's EEZ.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.255-268
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• 2016

Climate change has increased the need to secure a new water resource in addition to the traditional water resources such as surface water and ground water. The seawater desalination market is growing sharply in accordance with this situation in Korea, "seawater engineering & architecture of high efficiency reverse osmosis (SEAHERO)" program was launched in 2007 to keep pace with world market trend. SEAHERO program was completed in 2014, contributed to turn the domestic technology in evaporative desalination technology to RO desalination technology. Currently, it is investigated that the average specific energy consumption of the whole RO plant is around $3.5kWh/m^3$. The Busan Gi-jang plant has shown $3.7{\sim}4.0kWh/m^3$, including operational electricity for plant and maintenance building. Although not world top level, domestic RO technology is considered to be able to compete in desalination market. Separately, many researchers in the world are developing new technologies for energy savings. Various processes, forward osmosis (FO), membrane distillation (MD) process are expected to compete with RO in the future market. In Korea, FO-RO hybrid process, MD and pressure retarded osmosis (PRO) process are under development through the research program in Ministry of Land, Infrastructure and Transport (MOLIT). The desalination technology level is expected to decrease to $2.5kWh/m^3$.

• The KIPS Transactions:PartC
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• v.12C no.7 s.103
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• pp.949-958
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• 2005

In the paper we study key agreement schemes when a party needs to establish a session key with each of several parties, thus having multiple session keys. This situation can be represented by a graph, tailed a key graph, where a vertex represents a party and an edge represents a relation between two parties sharing a session key. graphs to establish all session keys corresponding to all edges in a key graph simultaneously in a single session. A key agreement protocol of a key graph is a natural extension of a two-party key agreement protocol. We propose a new key exchange model for key graphs which is an extension of a two-party key exchange model. using the so-called randomness re-use technique which re-uses random values to make session keys for different sessions, we suggest two efficient key agreement protocols for key graphs based on the decisional Diffie-Hellman assumption, and prove their securities in the key exchange model of key graphs. Our first scheme requires only a single round and provides key independence. Our second scheme requires two rounds and provides forward secrecy. Both are proven secure In the standard model. The suggested protocols are the first pairwise key agreement protocols and more efficient than a simple scheme which uses a two-party key exchange for each necessary key. Suppose that a user makes a session key with n other users, respectively. The simple scheme's computational cost and the length of the transmitted messages are increased by a factor of n. The suggested protocols's computational cost also depends on n, but the length of the transmitted messages are constant.

• 한국환경농학회:학술대회논문집
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• 2009.07a
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• pp.3-18
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• 2009

It is difficult for consumers to satisfy high safety request with post-management method such as inspection and surveillance, as various changes in-and-out of the country associated with food safety. In terms of food safety problems related to foods, it is crucial to recognize public health and consumer protection and construct pre-preventive Food Control System. A joint committee, FAO/WHO made the following consultations to the National Food Safety System. ${\circ}$ Approach entirely from farm to table ${\circ}$ Get ready for Risk Analysis System ${\circ}$ Secure transparency ${\circ}$ Establish the optimal policy by evaluating the effect of regulation When it comes to summarizing the consultation, it would be accumulated as two key words; "Efficiency" and "Credibility". Whereas the problem of efficiency focuses on precaution rather than post-management, it requires policy option to maximize consumer's benefit by evaluating the cost for the Food Safety Management and its benefit. Also, analyzing risk's character and amount, demanding an optimal means, and introducing scientific analysis system put much value on the stakeholder's communications are procedure's security which can satisfy both "Efficiency" and "Credibility" simultaneously. Especially, it is emphasized here that Risk Assessment need to be separated from Risk Management. This action is a valid means of credibility security throughout improving transparency. A number of nations and organizations have reformed the method of food management passing through reflection and examination of the prior National Food Safety Management since BSE occurred in Britain, 1996. FSA; Food Standard Agency, AFFSA, EFSA, BfR, and FSC are Risk Assessment Organization functionally separated from Risk Management Organization, JECFA, JMCFA, JMPR, JEMRA in Codex charge Risk Assessment internationally. In case of advanced countries excluding several those such as The U.S. and so forth, though these Risk Assessment Organizations are either separated functionally within Risk Management Organization or operated as apart organ, common factors are in which it has independence as Science Base. While securing independence of Risk Assessment Function, it is a tendency Risk Management should be functionally unified into efficiency as well. Though Germany constructs integral Risk Management System of diverse ways according to social and political conditions of each country such as GFOCP, DVFA, SNFA, CFIS and AQIS, there is a key word in the center, "Securing efficiency of Food Safety Management". However our nation has a representative plural；diversified system with The U.S., we took a step forward for unification as empowering policy's generalization；adjustment and Risk Assessment Function by means of enacting the "Food Safety Fundamental Law" in 2008 and establishing the "Food Safety Policy Commission" with private and governmental sectors in the Prime Minister's office. Even though the unification of Risk Management hereby increased, there is the lack of strengthening function of Risk Assessment and securing independence. It needs to be required for the professional committee in Food Safety Policy Commission to develop as a exclusive office of Risk Assessment by separating from a policy decision. Administrative Branches should reinforce feeble functions such as fundamental investigation；research for carrying out Risk Assessment with securing efficiency throughout reassessment of prior Risk Management Means.