• 한국컴퓨터정보학회논문지
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• 제25권10호
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• pp.77-86
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• 2020

본 논문에서는 블록체인 응용서비스를 견고하게 실행하고, 이의 실패 시 체계적인 복구를 지원하는 BR2K(Blockchain application, Replication & Recovery technique using Kubernetes)기법을 제안한다. 블록체인 서비스는 블록체인의 특징인 탈중앙화, 높은 보안성, 그리고 데이터 무결성 등을 기반으로 행정, 금융, 그리고 의료 시스템 같은 다양한 분야에서 개발 및 적용되고 있다. 따라서 이와 같이 서비스의 연속성이 중요한 분야에서 블록체인 서비스 실행에 대한 견고성이 제공하는 것이 필요하며, 서비스 실패에 대한 복구 방안 또한 필요한 실정이다. 이를 위하여, BR2K는 블록체인 응용서비스의 지속 가능한 실행을 체계적으로 지원하는 실행 복제 기법을 제공한다. 또한, 블록체인 서비스 레지스트리 기반의 견고한 컨테이너 레지스트리를 소개하고 이를 이용하여 서비스 실패에 대한 복구를 체계적으로 지원한다. 더불어, 블록체인 서비스 개발 프레임워크인 트러플을 쿠버네티스 컨테이너 관리 도구를 활용할 수 있도록 확장하고, 이를 바탕으로 서비스를 신속하게 배포하는 기법을 제공한다.

• International Journal of Computer Science & Network Security
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• 제21권4호
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• pp.255-263
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• 2021

Smart grid is a fully-automated, bi-directional, power transmission network based on the physical grid system, which combines sensor measurement, computer, information communication, and automatic control technology. Blockchain technology, with its security features, can be integrated with Smart Grids to provide secure and efficient power management and transmission. This paper dicusses the deployment of Blockchain technology in Smart Grid. It presents application areas and protocols in which blockchain can be applied to in securing smart grid. One application of each area is explored in detail, such as efficient peer-to-peer transaction, lower platform costs, faster processes, greater flexibility in power generation to transmission, distribution and power consumption in different energy storage systems, current barriers obstructing the implementation of blockchain applications with some level of maturity in financial services but concepts only in energy and other sectors. Wide range of energy applications suggesting a suitable blockchain architecture in smart grid operations, a sample block structure and the potential blockchain technicalities employed in it. Also, added with efficient data aggregation schemes based on the blockchain technology to overcome the challenges related to privacy and security in the smart grid. Later on, consensus algorithms and protocols are discussed. Monitoring of the usage and statistics of energy distribution systems that can also be used to remotely control energy flow to a particular area. Further, the discussion on the blockchain-based frameworks that helps in the diagnosis and maintenance of smart grid equipment. We have also discussed several commercial implementations of blockchain in the smart grid. Finally, various challenges have been discussed for integrating these technologies. Overall, it can be said at the present point in time that blockchain technology certainly shows a lot of potentials from a customer perspective too and should be further developed by market participants. The approaches seen thus far may have a disruptive effect in the future and might require additional regulatory intervention in an already tightly regulated energy market. If blockchains are to deliver benefits for consumers (whether as consumers or prosumers of energy), a strong focus on consumer issues will be needed.

• 한국빅데이터학회지
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• 제6권2호
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• pp.151-159
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• 2021

블록체인 네트워크를 구축하려면 다양한 유형의 IT 지식과 기술이 필요할 뿐 아니라 장시간의 번거로운 과정이 필요하다. 이러한 한계를 극복하기 위해 MS사와 같은 글로벌 IT 기업들은 클라우드 기반 블록체인 서비스를 제공하고 있다. 본 논문에서는 블록체인 개발자, 블록체인 운영자와 기업이 자신의 인프라에 블록체인을 보다 편안하게 배치할 수 있도록 하는 블록체인 기반 구축 및 관리 도구를 제안한다. 이 도구는 대표적인 프라이빗 블록체인 플랫폼 중 하나인 Hyperledger Fabric과 네트워크 전체 배포를 지원하는 오픈소스 IT 자동화 엔진인 Ansible을 사용하여 구현한다. 복잡하고 반복적인 텍스트 명령 대신 사용자가 블록체인 네트워크를 원활하게 설정, 배포 및 상호 작용할 수 있는 사용자 친화적인 웹 대시보드 인터페이스를 제공한다. 이 제안된 솔루션을 통해 블록체인 개발자, 운영자 및 블록체인 연구자는 블록체인 인프라를 보다 쉽게 구축하여 시간과 비용을 절약할 수 있다. 제안된 도구의 유용성과 편의성을 검증하기 위해 전자투표를 수행하는 블록체인 네트워크를 구축하여 테스트하였다. 10개 이상의 설정 파일을 작성하고 수백 줄에 걸쳐 명령을 실행하는 블록체인 네트워크 구성을 그래픽 사용자 인터페이스에서 간단한 입력 및 클릭 조작으로 대체할 수 있어 사용자의 편의성과 구축시간을 절약을 확인할 수 있었다. 제안된 블록체인 도구는 앞으로 식품안전 공급망 구축 등 다양한 분야에서 신뢰 데이터 인프라 구축에 활용될 예정이다.

• Journal of Information Technology Applications and Management
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• 제27권3호
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• pp.1-18
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• 2020

Recently, following the development of FinTech technology that combines finance and information and communication technology, the need and social demands for a block chain technology-based trading system have increased significantly. In this study, a research model was developed and hypothesized through literature research on the concept of block chain technology, the technology acceptance model, and the unified theory of acceptance and use of technology. The research theories were tested by collecting data through surveys and analyzing the collected data. This study conducted empirical research to identify the factors influencing the user acceptance intention and utilization behavior of the block chain technology in introducing the block chain technology. First, factors affecting the acceptance intention of the blockchain user were performance expectation, effort expectation, social impact, and blockchain transparency variables. Second, the facilitation conditions and stakeholder confidence variables were analyzed as factors that did not affect the acceptability of the blockchain users. Third, variables such as blockchain transparency, stakeholder trust and intention of acceptance are factors that affect the usage behavior of the blockchain. Fourth, it was confirmed that the acceptance intention had a very high explanatory power on usage behavior of Blockchain technology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권8호
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• pp.3766-3788
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• 2017

A blockchain is an underlying technology and basic infrastructure of the Bitcoin system. At present, blockchains and their applications are developing rapidly. However, the basic research of blockchain technology is still in the early stages. The efficiency and reliability of blockchain communication is one of the research problems that urgently need to be studied and addressed. Existing algorithms may be less feasible for blockchain-based communication because they only consider a single communication factor (node communication capability or node trust degree) and only focus on a single communication performance parameter(communication time or communication reliability). In this paper, to shorten the validation time of blockchain transactions and improve the reliability of blockchain-based communication, we first establish a multi-link concurrent communication model based on trust degree, and then we propose a novel integrated factor communication tree algorithm (IFT). This algorithm comprehensively considers the node communication link number and the node trust degree and selects several nodes with powerful communication capacity and high trust as the communication sources to improve the concurrency and communication efficiency. Simulation results indicate that the IFT algorithm outperforms existing algorithms. A blockchain communication routing scheme based on the IFT algorithm can increase communication efficiency by ensuring communication reliability.

• Journal of Information Processing Systems
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• 제16권4호
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• pp.935-958
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• 2020

The core value of finance is credit. It can be said that without credit, there can be no finance. The distributed structure of the blockchain and the low-cost trust-building mechanism based on mathematical algorithms provide a new solution and path for solving and optimizing related problems in the financial field. The blockchain technology is applied in the development of the financial industry through consensus mechanisms, smart contracts, and distributed networks. In this research, a comprehensive survey of the blockchain technology is proposed in the development of financial services including equity crowdfunding and credit investigations in inclusive finance, cross-border remittance, Internet financial payment, P2P lending, supply chains finance, and the application of blockchain in the field of anti-money laundering. This paper discusses the role of blockchain in solutions to different issues in the financial field. It also discusses the architectures in different financial service application scenarios from the perspective of the financial trust mechanism and the perspective of the technology and rule change of blockchain participation in financial innovation. Finally, the problems and challenges of blockchain in financial services are discussed, and corresponding solutions are proposed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2865-2878
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• 2021

As a current popular technology, the blockchain has a serious issue: the private key cannot be retrieved due to force majeure. Since the outcome of the blockchain-based Bitcoin, there have been many occurrences of the users who lost or forgot their private keys and could not retrieve their token wallets, and it may cause the permanent loss of their corresponding blockchain accounts, resulting in irreparable losses for the users. We propose a recoverable private key scheme for consortium blockchain based on the verifiable secret sharing which can enable the user's private key in the consortium blockchain to be securely recovered through a verifiable secret sharing method. In our secret sharing scheme, users use the biometric keys to encrypt shares, and the preset committer peers in the consortium blockchain act as the participants to store the users' private key shares. Due to the particularity of the biometric key, only the user can complete the correct secret recovery. Our comparisons with the existing mnemonic systems or the multi-signature schemes have shown that our scheme can allow users to recover their private keys without storing the passwords accurately. Hence, our scheme can improve the account security and recoverability of the data-sharing systems across physical and virtual platforms that use blockchain technology.

• Journal of Multimedia Information System
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• 제8권3호
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• pp.197-202
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• 2021

Bitcoin and blockchain are often making headlines not only on TV or media but also among the public in today's society. These technologies have been developed after the risk of the centralized financial system came to the fore during the 2007 global financial crisis. Since then, an anonymous inventor called Satoshi Nakamoto penned the bitcoin white paper where a blockchain-based reference implementation was introduced. Bitcoin was able to achieve unprecedented growth by positioning itself as one of the top global currencies in terms of market capitalization after five years since its development. The pace of Vietnam's economic development is notably fast among Asian nations, while the nation was expected to be a Southeast Asian blockchain hub but they have banned virtual currency trading recently. However, they've also designated the State Bank of Vietnam (SBV) as a responsible agency for the research of blockchain-based cryptocurrencies, the construction of a service ecosystem, and their test operations. The fast-growing economy, increasing number of smartphone users, and the Vietnam government's support policies for startups substantiate these efforts. Therefore, this paper attempts to study the current status of Vietnam's blockchain technology that has been considered to be the center of blockchain systems right behind Singapore, and its implications for Korean companies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.4093-4107
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• 2019

Proof of Work (PoW) based blockchains have limitations in throughput, time consumption, and energy efficiency. In these systems, a miner will consume significant time and resources to obtain a reward for contributing to the blockchain. To overcome these limitations, recent research on blockchains are focused on accelerating the speed, scalability, and enhancing the security level. By enhancing specific procedures of blockchain system, the level of data integrity supported by the blockchain can become more robust, and efficient. In this paper, a new blockchain consensus model based on the Bryllite Consensus Protocol (BCP) is proposed to support a hyper-connected massively multiplayer online game (MMOG) ecosystem. The BCP scheme enables users to participate directly in new consensus processes through a Proof of Participation (PoP) algorithm. In this model, the consensus algorithm has a simpler form while maintaining high security level. In addition, because the BCP scheme gives users an equal chance to make a contribution to the blockchain, rewards are distributed in an equal fashion, which motivates user participation. The analysis of the proposed scheme is applied to the Bryllite consortium blockchain system (homed in Hong Kong), which is a new blockchain network developed for international game industries, gamers, and game events.

• 한국컴퓨터정보학회논문지
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• 제23권12호
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• pp.49-55
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• 2018

In this paper, we propose schemes of blockchain utilization in tactical communication environment. The military tactical communication environment has similar characteristics with blockchain network such as distributed architecture, decentralization, and the need for data integrity. A communication node constituting a tactical communication network is constituted by a system capable of configuring and connecting a network for each node. When a communication node, having such capabilities, is configured as a node of blockchain network, various functions could be performed. In this paper, we propose utilization schemes of authentication, integrity, record management, and privilege control based blockchain technology. Functions for authentication, integrity verification, and record management need to ensure the stored data and could track history. The requirement of function's characteristics are matched to blockchain which is storing data sequentially and difficult to hack data, so that it could perform functionally and sufficiently well. Functions for authority control should be able to assign different privileges according to the state of the requestor. Smart contract will function when certain conditions are satisfied and it will be able to perform its functions by using it. In this paper, we will look over functions and utilization schemes of blockchain technology which could reliably share and synchronize data in a tactical communication environment composed of distributed network environment.