• Journal of the Korea Institute of Information Security & Cryptology
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• v.34 no.2
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• pp.289-299
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• 2024

Blockchains are not efficient for real-time processing because the growing number of transactions and users delays many computations and network communications. This study proposes a cloud proxy server, so that legitimate users can use blockchain as well as reduce network latency. To proceed with a blockchain transaction, the blockchain copy server verifies all transaction-related data, but the cloud proxy server verifies legitimate users with a simple zero-knowledge proof algorithm, enabling efficient blockchain real-time processing. The cloud proxy server can support blockchain anonymity, security, and scalability that can verify legitimate users with the proposed zero-knowledge proof by receiving the registered key pair of the blockchain user. In the proposed research analysis, blockchain-based cloud proxy server reduces network latency compared to previous studies and key processing on cloud proxy servers reduces the cost of key computation compared to previous studies.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.1060-1061
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• 2019

블록체인은 2009년 이후 여러 산업군(금융, 유통, 암호화폐등)에서 만들어졌으며 특정 사업에서 utility기능을 수행하는 것을 목표로 개발되고 유통되고 있다. 하지만 블록체인은 실생활에 사용하기에 아직 많은 제약이 존재하기 때문에 활성화가 안 되고 있다. 본 연구는 블록체인의 운용 시 존재하는 여러 제약들을 블록체인 승인시스템을 통하여 해결하고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.01a
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• pp.413-414
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• 2019

국내외 기관 및 기업 간 거래를 위하여 블록체인기술 적용이 활성화되고 있다. 특히 국내의 문화 콘텐츠의 다국적 기업대상 거래 시 블록체인을 통한 스마트 컨트랙트 기술로 거래의 투명성과 안정성을 높일 수 있다. 본 논문에서는 디지털 콘텐츠 거래를 위하여 블록체인 이더리움 기술을 활용한 스마트 컨트랙트 적용 방법을 제안한다. 구현된 기술을 통하여 다기업간 신뢰성 있는 디지털 콘텐츠의 거래를 가능하게 하고 국내외의 문화 콘텐츠 거래를 활성화 할 수 있다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.6
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• pp.981-997
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• 2020

Blockchain technology can provide a high level security based on a decentralized distributed ledger and consensus-based structure. In order to increase the utilization of blockchain technology, it is necessary to find a way to use it in fields that require personal data processing such as health care and e-commerce. To achieve this goal, the blockchain based system should be able to comply with data privacy regulations represented by European Union(EU)'s GDPR(General Data Protection Regulation). However, because of the properties of the blockchain like the immutability and decentralized recorded data, it is difficult to technically implement the requirements of the existing privacy regulations on the blockchain. In this paper, we propose a multi-chain based access control system that can guarantee the rights of the personal data subject required by GDPR by utilizing Chameleon Hash and Attribute Based Encryption (ABE). Finally, we will show through security analysis that our system can handle personal data while maintaining confidentiality and integrity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1264-1270
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• 2018

Blockchain is a technology that directly connects each node to P2P method, except for the central server. A public blockchain is one of the blockchain types, anyone can participate without any restriction. If some node find nonce, which node can broadcasted data to all nodes. At this time, if a node that finds a nonce hides malicious code in the block, all nodes participating in the chain may be infected with malicious code due to the characteristics of the decentralization system of the blockchain. In this paper, to solve the problem that hackers can participate as an any node, we propose that a user with malicious intent can not participate as a node through a firewall with AI technology. This will improve the reliability of the propagated data over existing data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.43-50
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• 2019

Block-chain enjoys technical advantages such as "robust security," owing to the structural characteristic that forgery is impossible, decentralization through sharing the ledger between participants, and the hyper-connectivity connecting Internet of Things, robots, and Artificial Intelligence. As a result, public organizations have highly positive attitudes toward the adoption of technology using block-chain, and the design of university information services is no exception. Universities are also considering the application of block-chain technology to foundations that implement various information services within a university. Through case studies of block-chain applications across various industries, this study designs an empirical model of an integrated information service platform that integrates information systems in a university. A basic road map of university information services is constructed based on block-chain technology, from planning to the actual service design stage. Furthermore, an actual empirical model of an integrated information service in a university is designed based on block-chain by applying this framework.

• The Journal of the Korea Contents Association
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• v.18 no.7
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• pp.620-627
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• 2018

With the widespread adoption of blockchain in the field of business, the importance of confidentiality of critical information has been emerging. Although blockchain models solve the security problem regarding integrity threat by sharing transactions and making them public, it is vulnerable in terms of confidentiality. Therefore, a security mechanism to provide confidentiality of critical information and private information of a firm is necessary to utilize block chain in the process of work. In order to solve the problem, we suggest Private blockchain based cryptographic protocol application model using Smart contract commitment scheme of the Ethereum. It can contribute to activation of blockchain services by enabling non-trusted participants to perform businesses through application of smart contract enhanced in terms of confidentiality and integrity to private blockchain.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.219-227
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• 2019

This study aims to examine Blockchain research trend using bibliometrics-based network analysis. The data were collected from WoS, Scopus, Korea Citation Index and National science & Technology Information Service, from 2009 to 2018. As results, the number of publications has started increasing rapidly from 2017 and it showed the initial stage of formation of coauthor network. Words often used in the title of the publications were related to application development, controversy and technology development. In addition, the majority of domestic papers are in the subject of social science, while international papers tend to focus on engineering issues. The results of the temporal analysis show that Korean researchers' block chain 3.0 started in 2017 and are rapidly increasing in 2018. The number of citations was associated with publication year in a statistically signifiant way. By examining these research trends, we hope that this paper can be a useful basis for the development of blockchain. Future research is expected to reveal more clearly the knowledge structure and characteristics of blockchain around the world.

• Journal of Industrial Convergence
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• v.21 no.8
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• pp.51-58
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• 2023

Blockchains have recently struggled to design for the ideal distributed trust networks by solving scalability trilemma. However, local conflicts between some countries lead to imbalance on energy distribution. Besides, blockchain networks (e.g., Bitcoin) currently consume enormous energy for transaction and mining. The existing data volume based trust model evaluated an increasing blockchain size better than Lubin's trust model in scalability trilemma. In this paper, we propose a scalability based energy model to evaluate sustainability for blockchain networks, considering energy consumption for transaction, time duration, and the blockchain size of growing blockchain networks. Through the rigorous numerical analysis, we compare the proposed scalability based energy model with the existing model for the satisfaction and optimal blockchain size. Thus, the scalability based energy model will provide an assessment tool to choose the proper blockchain networks to solve scalability trilemma problem and prove sustainability.

• The Journal of Society for e-Business Studies
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• v.27 no.1
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• pp.95-109
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• 2022

A blockchain based platform can ensure data integrity, reliability, and security by applying distributed processing and encryption technology for transaction records. In the existing knowledge sharing platform, the created knowledge could not be shared or utilized sufficiently due to information asymmetry and centralization. However little research has been done so far on this area. In this study, we will examine case studies and development potentials for blockchain based knowledge sharing platforms based on previous studies of blockchain technology, token economy, knowledge sharing, motivation theory, and social exchange theory. Blockchain based platforms can contribute to the activation of knowledge sharing, by resolving information asymmetry, simplifying unnecessary work procedures through unified knowledge sharing flow and excluded centralization of authority by decentralization, and strengthening access and utilization of the knowledge produced by the platform.