• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.5
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• pp.889-899
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• 2021

This paper proposes a reliable data sharing scheme on the internet of vehicles (IoV) by utilizing blockchain technology for constructing a decentralized system approach. In our model, to maintain the credibility of the information messages sent by the vehicles to the system, we propose a reputation rating mechanism, in which neighboring vehicles validate every received information message. Furthermore, we incorporate an incentive mechanism based on smart contracts, so that vehicles will get certain rewards from the system when they share correct traffic information messages. We simulated the IoV network using a discrete event simulator to analyze network performance, whereas the incentive model is designed by leveraging the smart contract available in the Ethereum platform.

• Journal of the Semiconductor & Display Technology
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• v.18 no.1
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• pp.74-78
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• 2019

As software becomes larger and network technology develops, the management of distributed data becomes more popular. Therefore, it is becoming increasingly important to use blockchain technology that can guarantee the integrity of data in various fields by utilizing existing infrastructure. Blockchain is a distributed computing technology that ensures that servers participating in a network maintain and manage data according to specific agreement algorithms and rules to ensure integrity. As smart contracts are applied, not only passwords but also various services to be applied to the code. In order to reinforce existing research on smart contract applied to the blockchain, we proposed a dynamic conditional rule of smart contract that can formalize rules of smart contract by introducing ontology and SWRL and manage rules dynamically in various situations. In the previous research, there is a module that receives the upper rule in the blockchain network, and the rule layer is formed according to this module. However, for every transaction request, it is a lot of resources to check the top rule in a blockchain network, or to provide it to every blockchain network by a reputable organization every time the rule is updated. To solve this problem, we propose to separate the module responsible for the upper rule into an independent server. Since the module responsible for the above rules is separated into servers, the rules underlying the service may be transformed or attacked in the middleware. Therefore, the security mechanism using TLS and PKI is added as an agent in consideration of the security factor. In this way, the benefits of computing resource management and security can be achieved at the same time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.115-121
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• 2020

As the participation of blockchain increases, governance to maintain the ecosystem is being activated. Governance must be managed/supervised to maintain and improve the blockchain. However, as the usage of blockchain increases, there is a limit for people to manage it individually. In addition, smart contracts applied from Ethereum need to be verified for trade that are determined according to status values, as new trade types are possible. This research proposes a surveillance system, Blockchain Watchdog, based on the state monitoring of the blockchain smart contract as a tool for maintaining and developing the blockchain ecosystem of governance, and implemented and tested the surveillance system. As a case study, we conducted experiments on Ropsten and Ganache, and were able to see real-time information collection and visualization using dashboards, graphs, and charts. We expect to contribute to the maintenance and development of the ecosystem of blockchain governance through Blockchain Watchdog.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.4
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• pp.89-100
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• 2020

In order to reduce the time and cost used in insurance processing, studies have been actively carried out to apply blockchain smart contract technology to car insurance. However, by using traffic data that is insufficient to prove accidents, existing studies are being exposed to the risk of insurance fraud, such as forgery and overstated damage by malicious insurers. To solve this problem, we propose an accident data-based reliability estimation model by using both various types of data through sensors, RSUs, and IoT devices embedded in automobiles and smart contracts. In particular, the regression model was applied in consideration of the weight estimation according to the type of traffic accident data and the reliability estimation model trained according to various accident situations. The proposed model is expected to effectively reduce fraud and insurance litigation while providing transparency in the insurance process and streamlining it is well.

• Journal of the Korea Society of Computer and Information
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• v.28 no.1
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• pp.79-86
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• 2023

Construction is one of the oldest fields of providing human living comfort. However, despite the continuous development not only in IT but also in other fields, productivity degradation due to low automation is still serious. In particular, the use of the 4th industrial revolution technologies in construction is just beginning. Blockchain, which is one of the 4th industrial revolution technologies, is a type of a distributed database that is used to replicate, share, and synchronize data spread across different geographical locations, such as multiple sites, countries, or organizations. In this paper, we introduce the block chain and analyze use cases according to seven themes in construction. As a result of the analysis, it is expected to increase the understanding of blockchain in construction and provide usefulness for the development of various services in the future.

• Journal of Korea Multimedia Society
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• v.23 no.2
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• pp.262-273
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• 2020

This paper analyzes the existing copyright management and copyright sharing model and discusses the limitations. It then proposes a consortium Blockchain-based copyright management model in which the service platform participates as a node, and discusses how to combine the My Data concept with Blockchain and smart contracts. Also, Blockchain-based CP-ABE is introduced and applied to the proposed model as a way for users to define access policies and store copyright data in encrypted form on the storage of the online service providers (OSP). Compared with the existing copyright management model, the proposed model allows the copyright holder to focus on copyright registration, license content design, and sharing, as the data subject. And it is expected to be able to transparently manage the usage records and the basis for the settlement of the copyrighted data that are shared and used on each platform.

• Journal of Information Processing Systems
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• v.16 no.4
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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.

• ETRI Journal
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• v.43 no.2
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• pp.357-370
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• 2021

The evolution of blockchain-based systems has enabled researchers to develop nextgeneration e-voting systems. However, the classical consensus method of blockchain, that is, Proof-of-Work, as implemented in Bitcoin, has a significant impact on energy consumption and compromises the scalability, efficiency, and latency of the system. In this paper, we propose a hybrid consensus model (PSC-Bchain) composed of Proof of Credibility and Proof of Stake that work mutually to address the aforementioned problems to secure e-voting systems. Smart contracts are used to provide a trustworthy public bulletin board and a secure computing environment to ensure the accuracy of the ballot outcome. We combine a sharding mechanism with the PSC-Bchain hybrid approach to emphasize security, thus enhancing the scalability and performance of the blockchain-based e-voting system. Furthermore, we compare and discuss the execution of attacks on the classical blockchain and our proposed hybrid blockchain, and analyze the security. Our experiments yielded new observations on the overall security, performance, and scalability of blockchain-based e-voting systems.

• Convergence Security Journal
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• v.23 no.1
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• pp.63-68
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• 2023

In this study, in relation to blockchain protocol and network security, we study the configuration of blockchain and encryption key management methods on smart contracts so that we can have a strong level of response to MITM attacks and DoS/DDoS attacks. It is expected that the use of blockchain technology with enhanced security can be activated through respond to data security threats such as MITM through encryption communication protocols and enhanced authentication, node load balancing and distributed DDoS attack response, secure coding and vulnerability scanning, strengthen smart contract security with secure consensus algorithms, access control and authentication through enhanced user authentication and authorization, strengthen the security of cores and nodes, and monitoring system to update other blockchain protocols and enhance security.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.108-126
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• 2023

This study explored the sustainability of a blockchain-based cultural art performance video platform through the construction of Gyeonggi Art On, a new media art broadcasting station in Gyeonggi-do. In addition, the technical limitations of video content transaction using block chain, legal and institutional issues, and the protection of personal information and intellectual property rights were reviewed. As for the research method, participatory observation methods such as in-depth interviews with developers and operators and participation in meetings were conducted. The researcher participated in and observed the entire development process, including designing and developing blockchain nodes, smart contracts, APIs, UI/UX, and testing interworking between blockchain and content distribution services. Research Question 1: The results of the study on 'Which technology model is suitable for a blockchain-based performance video content distribution public platform?' are as follows. 1) The blockchain type suitable for the public platform for distribution of art performance video contents based on the blockchain is the private type that can be intervened only when the blockchain manager directly invites it. 2) In public platforms such as Gyeonggi ArtOn, among the copyright management model, which is an art based on NFT issuance, and the BC token and cloud-based content distribution model, the model that provides content to external demand organizations through API and uses K-token for fee settlement is suitable. 3) For public platform initial services such as Gyeonggi ArtOn, a closed blockchain that provides services only to users who have been granted the right to use content is suitable. Research question 2: What legal and institutional problems should be reviewed when operating a blockchain-based performance video distribution public platform? The results of the study are as follows. 1) Blockchain-based smart contracts have a party eligibility problem due to the nature of blockchain technology in which the identities of transaction parties may not be revealed. 2) When a security incident occurs in the block chain, it is difficult to recover the loss because it is unclear how to compensate or remedy the user's loss. 3) The concept of default cannot be applied to smart contracts, and even if the obligations under the smart contract have already been fulfilled, the possibility of incomplete performance must be reviewed.