• 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.

• Journal of Information Processing Systems
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• v.19 no.2
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• pp.240-257
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• 2023

The industrial Internet of Things (IIoT) is characterized by intelligent connection, real-time data processing, collaborative monitoring, and automatic information processing. The heterogeneous IIoT devices require a high data rate, high reliability, high coverage, and low delay, thus posing a significant challenge to information security. High-performance edge and cloud servers are a good backup solution for IIoT devices with limited capabilities. However, privacy leakage and network attack cases may occur in heterogeneous IIoT environments. Cloud-based multi-party computing is a reliable privacy-protecting technology that encourages multiparty participation in joint computing without privacy disclosure. However, the default cloud selection method does not meet the heterogeneous IIoT requirements. The server can be dishonest, significantly increasing the probability of multi-party computation failure or inefficiency. This paper proposes a blockchain and smart contract-based optimized cloud node selection framework. Different participants choose the best server that meets their performance demands, considering the communication delay. Smart contracts provide a progressive request mechanism to increase participation. The simulation results show that our framework improves overall multi-party computing efficiency by up to 44.73%.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.635-638
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• 2018

The Cost for introducing smart factory will decrease and the service type will change from a large scale to small quantity manufacturing, when 3D printing technologies have actively applied and smart factory related technologies have more stably developed. If customers have to provide private information, the availability of developed technology may cause slow progress. We propose a new protocol for custom manufacturing service of smart factory. The proposed approach is designed for smart contract based IoT convergence network. We analyzed the requirements of the proposed approach which provides anonymity, privacy, fairness, and non-repudiation. We compared it with closely related studies to show originality and differences.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.2
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• pp.215-222
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• 2019

Advances in technologies about 3D (three-dimensional) printing and smart factory related issues will have the effect of reducing the cost of building a smart factory and making various types of service available. Manufacturers and service providers of small assets work with outside experts to provide small amounts of customized ordering services. If customers have to disclose their private information to subscribe to a new service, they may be reluctant to use it and the availability of developed technology may cause slow progress. We propose a new protocol for customized order service for smart factory. The proposed approach is designed to meet requirements of security and based on smart contract in IoT convergence network. We analyzed the requirements of the proposed approach which provided anonymity, privacy, fairness, and non-repudiation. We compared it with closely related studies to show originality and differences.

• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.1-11
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• 2022

In this paper, we propose an NFT(Non-Fungible Token)-based access control method for safely sharing data between users in blockchain environment. Since all data stored in the blockchain can be accessed by anyone due to the nature of the technology, it is necessary to control access except for authorized users when sharing sensitive data. For that, we generate each data as NFT and controls access to the data through the smart contract. In addition, in order to overcome the limitations of single ownership of the existing NFT, we separated the NFT into ownership and use rights, so that data can be safely shared between users. Ownership is represented as an original NFT, use rights is represented as a copied NFT, and all data generated as NFT is encrypted and uploaded, so data can be shared only through the smart contract with access control. To verify this approach, we set up a hypothetical scenario called Building Information Modeling (BIM) data trade, and deployed a smart contract that satisfies 32 function call scenarios that require access control. Also, we evaluated the stability in consideration of the possibility of decryption through brute-force attack. Through our approach, we confirmed that the data can be safely shared between users in blockchain environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.97-103
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• 2019

Electronic contract systems are widely used to integrate and manage the contract management process based on the development of ICT technology. Recently, improvement methods using block chain technology are being studied. However, contract management systems have processing performance, security vulnerabilities, data entry, and service accessibility issues. In this paper, we propose a block - chain based contract management platform with block chain, smart contract, and Rest API. The suggested platform includes the RPBFT algorithm which solves the processing performance and security vulnerability of the existing consensus authentication algorithm, and the algorithm to prevent data entry and enhance transparency of participants. The block-chain-based contract management platform proposed in this paper provides a use environment with improved processing performance, security, reliability, and transparency, and can be used through API without burdening construction. Therefore, The effect can be expected.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1038-1043
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• 2021

Guaranteed seafarer wage payment is essential to ensure a stable supply of seafarers. However, disputes over non-payment of wages to seafarers often occur. In this study, an automatic wage payment system was designed using a blockchain-based smart contract to resolve the problem of seafarers' wage arrears. The designed system consists of an information register, a matching processing unit, a review rating management unit, and wage remittance before deploying smart contracts. The matching process was designed to send an automatic notification to seafarers and shipowners if the sum of the weight of the four variables, namely wages, ship type/fishery, position, and license, exceeded a pre-defined threshold. In addition, a review rating management system, based on a combination of mean and median, was presented to serve as a medium to mutually fulfill the normal working conditions. The smart contract automatically fulfills the labor contract between the parties without an intermediary. This system will naturally resolve problems such as fraudulent advance payment to seafarers, embezzlement by unregistered employment agencies, overdue wages, and forgery of seafarers' books. If this system design is commercialized and institutionally activated, it is expected that stable wages will be guaranteed to seafarers, and in turn, the difficulties in human resources supply will be solved. We plan to test it in a local environment for further developing this system.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.75
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• pp.137-158
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• 2017

Traditional banking systems of transactions are being replaced by FfinTech. Block Chain System can be a key point in Fourth Industrial Revolution such as AI, Big Data, IOT and also can be used as a tools of smart contract or smart payment systems in International Trade. If banking regulation is to be liberalized FinTech would be more activated in Korea and various attempts would be available especially smart payment in business. There are so many levels to be achieved from the time of contract to the time of clearance. We cannot expect speed and range of IT advancement and international trade, Block Chain system will challenge the traditional banking process. First, Block Chain Payment system can be used in P2P, B2B transaction and also T/T in small business. Second, Bit Coin transaction can be available within the parties without the Trusted Third Party. Third, By using of Block Chain system Traditional International Trade process can be altered.

• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.109-116
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• 2020

Social media is growing rapidly as a means of promoting artists' artworks and a channel for sales. However, since social media is not fundamentally a platform designed for trading, it has various limitations that make it difficult to ensure trust and security in carrying out transactions. In this paper, it is proposed interoperability between social media and blockchain-based smart contract system that can record and preserve the artist's profile, information related to artworks and details of the contract on the blockchain. The proposed interoperability allows artwork trading participants on social media to maintain mutual trust and to conduct the contract transparently. Also, the proposed interoperability consists of an API provided by the social media developer or an open source API without having to modify existing social media. This study is expected to contribute to the growth of the art trading market on social media by complementing the art trading practices on social media.

• 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.