• KNOM Review
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• v.21 no.2
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• pp.18-25
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• 2018

Since the development of block-chain technology by Satoshi Nakamoto and Bitcoin pioneered a new cryptocurrency market, a number of scale of cryptocurrency have emerged. There are crimes taking place using the anonymity and vulnerabilities of block-chain technology, and many studies are underway to improve vulnerability and prevent crime. However, they are not enough to detect users who commit crimes. Therefore, it is very important to detect abnormal behavior such as money laundering and stealing cryptocurrency from the network. In this paper, the characteristics of the transactions and user graphs in the Bitcoin network are collected and statistical information is extracted from them and presented as plots on the log scale. Finally, we analyze visualized plots according to the Densification Power Law and Power Law Degree, as a result, present features appropriate for detection of anomalies involving abnormal transactions and abnormal users in the Bitcoin network.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.583-590
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• 2022

With the release of the Bitcoin source in 2009, cryptocurrencies are continuously developing and expanding the market. Recently, new applicability is expanding centered on NFT coin and metaverse payment service. In particular, the Central Cryptocurrency Exchange actively supports relay transactions between cryptocurrencies or between traditional fiat currencies and cryptocurrencies. The cryptocurrency trading market based on such a central exchange encouraged speculative factors of cryptocurrencies, strongly arousing speculation and futility of cryptocurrencies. In addition, the central cryptocurrency exchange induces the centralization of users and virtual assets, thereby hindering the decentralization and security enhancement strategies of the block chain. Therefore, this study describes the current status and problems of centrally controlled centralized cryptocurrency exchanges in service, and presents a distributed cryptocurrency exchange modeling strategy and major issues as a decentralization model of the exchange. This research can strengthen the anonymity, decentralization, and autonomy of cryptocurrency based on blockchain.

• Journal of Industrial Convergence
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• v.20 no.10
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• pp.17-24
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• 2022

Lora, a non-band network technology of the long-distance wireless standard LPWAN standard, uses ABP and OTTA methods and AES-128-based encryption algorithm (shared key) for internal terminal authentication and integrity verification. Lora's recent firmware tampering vulnerability and shared-key encryption algorithm structure make it difficult to defend against MITM attacks. In this study, the consensus algorithm(PBFT) is applied to the Lora network to enhance safety. It performs authentication and PBFT block chain creation by searching for node groups using the GPS module. As a result of the performance analysis, we established a new Lora trust network and proved that the latency of the consensus algorithm was improved. This study is a 4th industry convergence study and is intended to help improve the security technology of Lora devices in the future.

• Korea Trade Review
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• v.46 no.6
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• pp.93-107
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• 2021

The bill of lading serves to link imports and exports. It is the last document issued in the export process and is the most important document before import and export as it is the first document required for importers to take over goods. Transfer the right to the goods to be transported to another person through endorsement. The role and importance of the bill of lading has already been suggested in many previous studies and the trading partners are fully aware of it. In addition, all countries and international organizations recognized the importance and enacted various laws and systems in relation to possible legal problems and they have become customary in practice. However, trade fraud that exploits the characteristics of the bill of lading may occur. In order to solve this problem, various attempts related to the electronic rights transfer of the bill of lading began to be carried out, and many institutions and companies are still trying to develop a new system. As a result of these efforts, electronic bills of lading, such as bolero, appeared, and electronic bills of lading, which can transfer rights in an electronic way, appeared. Therefore, this study intends to present the feasibility of the introduction of smart bills of lading after examining the current status of electronic bills of lading and the introduction of block chain technology-based bills of lading.

• The Journal of Society for e-Business Studies
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• v.24 no.3
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• pp.1-18
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• 2019

Due to the great advances in e-Marketplace and changes in type of items purchased from the online market, it has been dramatically increased the demand of the storage and transportation under the special conditions such as restricted temperature. Especially, the cold chain needs the way to transparently measure and monitor the entire network in realtime because it has a very complicated structure and requires totally different criteria at the every different steps and items. In this research, it has been presented the performance evaluation metrics to make contract using service level agreement (SLA), the way to apply the smart contract based on blockchain, the structure of blocks, service platform and application in order to build cold chain which can prevent the risk factors by measuring and sharing information in realtime using block chain technology. In addition, we have proposed the way to store the measured performance and reputation of each player in the block using smart contract based on SLA. With the presented framework, all players including service providers as well as users can secure the information for making the rational decisions. When the service platform is actually built and operated, it seems possible to secure the information in transparently and realtime. Also, it is possible to prevent the risk factors or prepare the preemptive plans to react on them.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.228-231
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• 2017

최근 랜섬웨어 같은 치명적 신 변종 사이버공격에 의한 경제적 피해가 심각해지고 있는 실정이며, 취약 홈페이지에 대한 위 변조 공격은 사용자 PC의 악성코드 감염 경로로 활용되고 있다. 본 연구에서는 소스코드, 이미지 및 키워드 등 3가지 방식의 홈페이지 위 변조 검증을 수행하고 해당 결과를 블록체인 기반으로 관리하여 데이터의 투명성 보안성 안정성을 확보할 수 있는 프레임워크를 제시하고자 한다.

• Convergence Security Journal
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• v.19 no.3
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• pp.13-19
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• 2019

MANET has many security vulnerabilities because it consists of only mobile nodes using wireless. In particular, it is a very important factor determining network performance that excludes the participation of malicious nodes through accurate reliability measurements and authentication of nodes participating in the network. In this paper, we proposed a technique applied with blockchain technology in order to prevent forgery of authentication information for nodes participating in the network. And, an area-based hierarchical structure was applied to increase the efficiency of authentication for nodes and apply the optimal technique of block generation and exchange protocol. In addition, four data payloads were added to the block header in order to add authentication information for nodes in block. To improve the reliability by applying the blockchain technique to the hop-by-hop data transfer method between mobile nodes, blockchain exchange protocol through transaction creation, block packaging and verification processes were implemented. We performed the comparative experiment with the existing methods to evaluate the performance of the proposed method and confirmed the excellent performance by the experiment results.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.231-238
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• 2023

As the demand for distance education increases, interest in the management of learners' rights is increasing. Blockchain technology is a technology that guarantees the integrity of the learner's learning history, and enables learner-led learning control, data security, and sharing of learning resources. In this paper, we proposed a blockchain technology-based learning management system based on Hyperledger Fabric that can be verified through permission between nodes among blockchain platforms. Learning resources can be shared differentially according to the learning progress. Also the percentage of individual learners that can be managed. As a result of the study, the superiority of the platform in terms of convenience compared to the existing platform was demonstrated. As a result of the performance evaluation for the research in this paper, it was confirmed that the convenience was improved by more than 5%, and the performance was 4-5% superior to the existing platform in terms of learner satisfaction.

• International Journal of Computer Science & Network Security
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• v.24 no.5
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• pp.198-204
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• 2024

Correspondence security between IoT devices is a significant concern, and the blockchain makes the latest difference by reducing this matter. In the blockchain idea, the larger part or even all organization hubs check the legitimacy and precision of traded information before tolerating and recording them, regardless of whether this information is identified with monetary exchanges or estimations of a sensor or a confirmation message. In assessing the legitimacy of a traded information, hubs should agree to play out an uncommon activity. The chance to enter and record exchanges and problematic cooperation with the framework is fundamentally decreased. To share and access the executives of IoT devices data with disseminated demeanour, another confirmation convention dependent on block-chain is proposed, and it is guaranteed that this convention fulfils client protection saving and security. This paper highlights the recent approaches conducted by other researchers to secure the Internet of Things environments using blockchain. These approaches are studied and compared with each other to present their features and disadvantages.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.83-101
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• 2021

This study is to investigate, using AHP, what technologies should be applied first to Korean SMEs in order to respond to the 4th industrial revolution and change to a smart enterprise. To this end, technologies related to the 4th industrial revolution and smart factory are synthesized, and the classification criteria of Dae-Hoon Kim et al. (2019) are applied, but additional opinions of experts are collected and related technologies are converted to artificial intelligence (AI), Big Data, and Cloud Computing. As a base technology, mobile, Internet of Things (IoT), block chain as hyper-connected technology, unmanned transportation (autonomous driving), robot, 3D printing, drone as a convergence technology, smart manufacturing and logistics, smart healthcare, smart transportation and smart finance were classified as smart industrial technologies. As a result of confirming the priorities for technical use by AHP analysis and calculating the total weight, manufacturing companies have a high ranking in mobile, artificial intelligence (AI), big data, and robots, while service companies are in big data and robots, artificial intelligence (AI), and smart healthcare are ranked high, and in all companies, it is in the order of big data, artificial intelligence (AI), robot, and mobile. Through this study, it was clearly identified which technologies should be applied first in order to respond to the 4th industrial revolution and change to a smart company.