• Journal of Industrial Convergence
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• v.18 no.6
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• pp.147-154
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• 2020

It is difficult to educate the overall operation of public and private blockchains with different characteristics. Recently, most education for blockchain is targeted at public blockchains such as Bitcoin and Ethereum. However, in an actual business environment, a private blockchain such as HyperLedger Fabric is used because access to corporate data is controlled through user authentication. In the case of HLF-based education, it is necessary to understand various components that are not in the public blockchain, such as peers, orderers, and channels. In this paper, a lab framework for HLF is designed for an efficient and systematic understanding of the functions and operations. The framework consists of HLF network, chaincode, and decentralized software control functions. Through the framework, the network configuration, distribution and activation of chaincode, and dApp execution process were checked step by step, and it was very easy to understand the overall flow for blockchain services. In addition, it is expected that a systematic understanding of the overall flow will be possible even in future network expansion.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.292-294
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• 2021

In this study, we designed an authentication method that can perform authentication again by loading authentication data using a blockchain and comparing it with the authentication data in the future. To this end, after passing through the conventional ID and password input method and the widely used ARS authentication method, authentication is performed using biometric data stored in each user's terminal. After going through these steps, we chose a method of comparing the previously stored chain data with the recently authenticated data to perform final authentication and then reloading the authenticated data into the chain data. It is expected that this study will be able to suggest various authentication methods.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.759-764
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• 2021

Because sensitive and private information should be exchanged between electric vehicles and a V2G service provider, reliable communication channel is essential to operate Vehicle-to-Grid (V2G) system which considers battery of electric vehicles as a factor of smart grid. The block chain is a platform for cryptocurrency transaction and fully distributed database system running by only equivalent node in the network without help of any central management or 3^rd party. In this paper, the structure and operation method of the blockchain are investigated, and the application of the blockchain for the V2G system was also explained and analyzed.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.349-352
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• 2020

클라우드는 가상화 기술을 사용한 리소스의 유연성과 뛰아난 접근성을 장점으로 빅데이터, 딥러닝 등 여러 분야에서 클라우드를 사용하고 있다. 최근 클라우드와 결합된 IoT 시스템을 통해 시스템 관리, 데이터 처리 및 저장, 데이터를 이용한 빅데이터 활용 등 여러 방법으로 사용 할 수 있어 많은 관심을 받고 있다. 그러나 IoT 클라우드의 많은 활용에 따라 대규모 시스템화, 여러 사용자의 개인정보 저장 등의 이유로 많은 공격자의 표적이 되고있다. 여러 공격자의 공격을 방아하기 위해 IoT 클라우드 시스템은 블록체인, 보안 IoT 디바이스, 변형된 클라우드 모델등 여러 연구가 진행되고 있다. 본 논문에서는 최근 연구되고 있는 블록체인, 클라우드, IoT 시스템의 동향에 대해 조사하고, 기존에 연구되었던 기술을 바탕으로 효과적인 블록체인 기반의 IoT 클라우드 시스템을 제안한다. 제안하는 IoT 클라우드 시스템은 블록체인 기술을 사용하여 보안정책을 관리할 수 있어 신뢰성이 높으며, 클라우드 시스템이 작동하지 않을 경우 페일오버 기능을 수행할 수 있어 가용성이 뛰어나다.

• 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.

• Food Science and Industry
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• v.54 no.3
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• pp.132-144
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• 2021

Along with the rise in the value of cryptocurrency, the interest of the blockchain is very high. However, most people do not understand cryptocurrency and blockchain very well. In addition, due to this lack of understanding of the technology, ideas about how blockchain technology can be applied in the food industry may not come up. Therefore, this content describes the advantages of blockchain technology in terms of security, starting with the understanding and operation method of cryptocurrency and blockchain technology, and briefly describes the development of a blockchain system. And simple examples of how this blockchain technology can be applied to other industries are summarized, and examples used in the food industry are summarized. Finally, it was insisted that using such a blockchain technology can provide safe food to consumers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1676-1686
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• 2021

In this paper, we propose a general cross-chain solution based on the idea of modularity, abstraction, and layering, which decoupling the cross-chain function from the consensus algorithm and specific application logic, and utilize a Merkle proof to ensure the validity and legality of cross-chain operations. Since the underlying implementations of homogeneous and heterogeneous blockchains are different, we treat them separately. For homogeneous blockchains, we suggest a TCP-like cross-chain transport protocol (CCTP). While for heterogeneous blockchains, we present a method to construct the relay chain to realize the cross-chain function. The proposed scheme can enable the correct, effective, reliable, orderly, and timely transmission of cross-chain data. However, the essential difference between the operations within a single blockchain and the interoperability between different blockchains is that the trust domain is different. Cross-chain interoperation itself breaks the completeness of the blockchain, therefore, some efficiency and safety must sacrifice to trade-off.

• Journal of Platform Technology
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• v.9 no.1
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• pp.46-57
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• 2021

Recently, research has been actively conducted to utilize blockchain technology in various fields. In particular, blockchain-based smart contracts are applied to various automation systems that require reliability as they have the characteristics of recording data in a distributed ledger environment to verify the integrity and validity of data. However, blockchain does not provide data access control and information security because data is shared among network participants. In this paper, we propose a user dynamic access control mechanism utilizing smart contracts in blockchain environments. The proposed mechanism identifies the user's contextual information when accessing data, allocating the user's role and dynamically controlling the data access range. This can increase the security of the system and the efficiency of data management by granting data access dynamically at the time of user authentication, rather than providing the same services in roles assigned to each user group of the network system. The proposed mechanism is expected to provide flexible authentication capabilities through dynamic data access control by users to enhance the security of data stored within blockchain networks.

• 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 Advanced Navigation Technology
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• v.27 no.5
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• pp.594-609
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• 2023

This research introduces a novel approach to address the complexities of the 5G ceramic antenna manufacturing process through the utilization of a blockchain-based 5G ceramic antenna manufacturing (B-5GAM) architecture. By seamlessly integrating blockchain technology and smart contracts, this architecture enhances transparency, security, and efficiency within the realm of 5G ceramic antenna manufacturing. The impact of applying blockchain to enhance security measures, process efficiency, and overall reliability is evident, not only optimizing the production process but also establishing a robust foundation for future advancements in communication technology. Validation of the B-5GAM architecture was achieved by manufacturing 5G antennas and implementing blockchain and smart contracts through algorithm proposals, confirming their practicality in real manufacturing environments. The results of this study demonstrate the feasibility of employing blockchain and smart contracts in the field of 5G ceramic antenna manufacturing, confirming their potential to enhance manufacturing efficiency and reliability.