• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.280-291
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• 2018

Recently, various interactions have been actively conducted through sharing and expressing opinions among users in social networks. In this process, since malicious users and fault information spread misinformation, trust is reduced irrespective of their will. To solve this problem, studies have been conducted to determine the trust of a user through direct-connected users. In this paper, we propose a enhanced user indirect trust discrimination scheme considering the connection relation and influence of users. The proposed indirect trust computation scheme derives the user's area of interest through user interaction and reconstructs the existing network considering the user connection relationship. The final indirect trust is also detected by determining whether the user is a malicious user through the influence of the user. Through various performance evaluations, we show that the proposed scheme achieves better performance than the existing method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.1
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• pp.83-102
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• 2024

Recently, as the use of the cloud increases year by year and remote work within the enterprise has become one of the new types of work, the security of the cloud-based remote work environment has become important. The introduction of zero trust is required due to the limitations of the existing perimeter security model that assumes that everything in the internal network is safe. Accordingly, NIST and DoD published standards related to zero trust architecture, but the security requirements of that standard describe only logical architecture at the abstract level. Therefore, this paper intends to present more detailed security requirements compared to NIST and DoD standards by performing threat modeling for OpenStack clouds. After that, this research team performed a security analysis of commercial cloud services to verify the requirements. As a result of the security analysis, we identified security requirements that each cloud service was not satisfied with. We proposed potential threats and countermeasures for cloud services with zero trust, which aims to help build a secure zero trust-based remote working environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.731-751
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• 2021

The Internet of Things is a huge group of devices communicating each other and the interconnection of objects in the network is a basic requirement. Choosing a reliable device is critical because malicious devices can compromise networks and services. However, it is difficult to create a trust management model due to the mobility and resource constraints of IoT devices. For the centralized approach, there are issues of single point of failure and resource expansion and for the distributed approach, it allows to expand network without additional equipment by interconnecting each other, but it has limitations in data exchange and storage with limited resources and is difficult to ensure consistency. Recently, trust management models using fog nodes and blockchain have been proposed. However, blockchain has problems of low throughput and delay. Therefore, in this paper, a trust management model for selecting reliable devices in a fog-based IoT environment is proposed by applying IOTA, a blockchain technology for the Internet of Things. In this model, Directed Acyclic Graph-based ledger structure manages trust data without falsification and improves the low throughput and scalability problems of blockchain.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.6
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• pp.1087-1101
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• 2013

Most people are connected to Social Network Services (SNS) through smart devices. Social Network Services are tools that transport information fast and easily. It does not care where he or she comes from. A lot of information circulates and is shared on Social Network Services. but Social Network Services faults are magnified and becoming a serious issue. For instance, malicious users generate multiple IDs easily on Facebook and he can use personal information of others on purpose, because most people tend to undoubtedly accept friend requests. In this paper, we have specified research scope to Facebook, which is one of most popular Social Network Services in the world. We propose a way of minimizing the number of malicious actions on Facebook from malignant users and malicious bots by setting criteria and applying reputation system.

• Journal of Distribution Science
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• v.4 no.2
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• pp.123-144
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• 2006

For the property right's protection of the nation, the uncertainty's dissolution and the reliability's security of real estate trade are very important. With the life style's change, the market of real estate becomes diversification, and the level of the real estate trade becomes diversification. But compared with this, the trade system of the real estate has not broken away from the mode in the past yet. To cope with it actively, it needs to review the real estate trade form. Especially, it needs to investigate a plan that can advance the Agency Listing method. The Exclusive Agency Listing and the real estate Information Network System have been the usual system in some advanced countries like America, Japan. It is the system that establishes the real estate brokerage's trade order and encourages the execution for the real estate client's property right's protection and benefit offer. In our country, The Exclusive Agency Listing and the real estate Information Network System were created in the revised real estate brokerage law in 12, 1993. But because of varies of questions, it can not be settled down. So this paper will develop the characteristic factors of the Exclusive Agency Listing and the real estate Information Network System revitalization and examine the mutual relation depends on the factors. And these factors were studied through the proved analysis to the effecting made on the Agency function's consideration and real estate broker' trust and customer satisfaction. So depends on these, the existed value now will present the revitalization plan and political implication about the Exclusive Agency Listing and the real estate Information Network System.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.1
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• pp.47-57
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• 2015

Recently, Internet of Things (IoT) have become popular for research and development in many areas. IoT makes a new intelligent network between things, between things and persons, and between persons themselves. Social network service technology is in its infancy, but, it has many benefits. Adjacent users in a social network tend to trust each other more than random pairs of users in the network. In this paper, we propose recommendation technique using social network in Internet of Things environment. We study previous researches about information recommendation, IoT, and social IoT. We proposed SIoT_P(Social IoT Prediction) using social relationships and item-based collaborative filtering. Also, we proposed SR(Social Relationship) using four social relationships (Ownership Object Relationship, Co-Location Object Relationship, Social Object Relationship, Parental Object Relationship). We describe a recommendation scenario using our proposed method.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.704-710
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• 2007

This paper examines the operations of private housing developers (PHDs) based on Social Network Theory. PHDs need to choose the best consultants, contractors and suppliers (CCS) to make sure the project run and complete successfully. PHDs gather the scarce resources from the external environment through personal network. This research used the social network method which relies on alliances based on network, social, tie and trust. The more people/firm PHDs network with, the better chances of finding the right CCS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.465-476
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• 2020

This study used social network analysis to analyze trends and the knowledge structure of research in international trade. To this end, 4,840 keywords were extracted and analyzed from 1,797 papers contained in the Journal of Int'l Trade and Industry Studies, the Korea Trade Review, and the Journal of Korea Trade from 2003 to 2019. The results reveal that the distribution of keywords in the trade studies, as with other intellectual networks, followed a power-law distribution. Some differences were observed in the top 20 keywords across journals, with total factor productivity, economic growth, and Korea-US FTA ranking high only in the Journal of Int'l Trade and Industry Studies. Global value chain and trust emerged as a topic that attracted new researchers' attention in the 2011-2019 period. Interest in E-Trade, WTO, and internationalization has declined in recent years. The conventional international trade research trend analyses have predominantly featured qualitative analysis by descriptive method in general, but this study is meaningful in that it employs quantitative analysis using social network analysis techniques.

• Convergence Security Journal
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• v.20 no.1
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• pp.3-8
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• 2020

Blockchain can enhance data transparency and security through decentralized data management that is out of the centralized system. permissioned blockchain of the blockchain platform, only trust-based authorized nodes can participate in the distributed network. Considering the characteristics of the permissioned blockchain, it is necessary to consider the network communication speed, transaction finality agreement, and stability as a condition for selecting the consensus algorithm. The consensus algorithms of the permissioned blockchain environment are diverse such as PoA, PBFT, Raft, etc., but there are no various evaluation factors for selecting consensus algorithms. In this paper, various performance evaluation factors are proposed to analyze the characteristics of each consensus algorithm of the permissioned blockchain and to select an efficient consensus algorithm considering the characteristics of the user environment that composes the network. The proposed performance evaluation factor can consider the network speed, stability, and consensus of the finality agreement between nodes under the premise of trust. Through this, a more efficient blockchain network environment can be constructed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.87-93
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• 2013

MANET has the advantage of having the flexibility to build easily a network in a difficult situation that builds a wired network. But, data transmission errors by movement of nodes and eavesdropping by wireless communications have become a problem of security. Authentication service is the most essential in order to overcome these problems and operate network stably. In this paper, we propose 3-tiers authentication structure to exclude of malicious node and operate stable network through more systematic and thorough node authentication. After network is composed into a cluster, cluster head which play CA role is elected. Among these, the highest-CA is elected. The highest-CA receives certificates to cluster head and the cluster head evaluates trust value of their member nodes. Authentication technique which issues member node key is used. We compared PSS and experimented to evaluate performance of proposed scheme in this paper and efficiency of the proposed technique through experience was confirmed.