• Journal of Yeungnam Medical Science
• /
• v.39 no.2
• /
• pp.98-107
• /
• 2022

Background: Stroke patients usually experience damage to multiple functions and a long rehabilitation period. Hence, there is a large volume of patient clinical information. It thus takes a long time for clinicians to identify the patient's information and essential pieces of information may be overlooked. To solve this, we stored the essential clinical information of stroke patients in a blockchain and implemented the blockchain technology using the Java programming language. Methods: We created a mini blockchain to store the medical information of patients using the Java programming language. Results: After generating a unique pair of public/private keys for identity verification, a patient's identity is verified by applying the Elliptic Curve Digital Signature Algorithm based on the generated keys. When the identity verification is complete, new medical data are stored in the transaction list and the generated transaction is verified. When verification is completed normally, the block hash value is derived using the transaction value and the hash value of the previous block. The hash value of the previous block is then stored in the generated block to interconnect the blocks. Conclusion: We demonstrated that blockchain can be used to store and deliver the patient information of stroke patients. It may be difficult to directly implement the code that we developed in the medical field, but it can serve as a starting point for the creation of a blockchain system to be used in the field.

• Journal of Convergence for Information Technology
• /
• v.9 no.10
• /
• pp.9-15
• /
• 2019

Recently, in the field of next-generation e-commerce and finance, interest in blockchain-based technologies such as Bitcoin and Ethereum is great. Although the security of blockchain technology is known to be secure, hacking incidents / accidents related to cryptocurrencies are being issued. The main causes were vulnerabilities in the external environment, such as taking over login sessions on cryptocurrency wallets, exposing private keys due to malware infection, and using simple passwords. However, private key management recommends general methods such as utilizing a dedicated application or local backup and physical archiving through document printing. In this paper, we propose a white box password-based private key protection scheme. As a result of safety and performance analysis, we strengthened the security against vulnerability of private key exposure and proved the processing efficiency of existing protocol.

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

• Journal of Internet of Things and Convergence
• /
• v.8 no.5
• /
• pp.55-61
• /
• 2022

Today's payment systems are becoming unmanned and changing to a way of paying with kiosks. This has the advantage of convenient payment because consumers can select a menu and specify the number of products to be purchased with just a touch of the screen. However, from the point of view of system security, the actual kiosk system has various vulnerabilities. This can hijack the administrator account, gain system privileges, and perform malicious actions. In addition, it is exposed to a number of security threats, such as the possibility of wasting unnecessary resources by abnormally increasing the number of payments, and causing the device to fail to operate normally. Therefore, in this paper, if any node of a participant in the solana blockchain approves an incorrect fork, the stake of the voting nodes is deleted. Also, since all participants can see the transaction history due to the nature of the block chain, I intend to write a thesis on a system that improves the vulnerability of kiosk payments by separating the access rights through the private blockchain.

• Journal of Software Engineering Society
• /
• v.29 no.2
• /
• pp.7-12
• /
• 2020

A project to establish an information system with a project cost of more than 500 million won at a local public firm is subject to the Information System Audit (hereinafter referred to as IS Audit), and the IS Auditor shall conduct audit according to the audit criteria. Recently, as blockchain technology has been applied to various fields such as manufacturing, healthcare, distribution, and public sectors beyond the financial industry, the development of systems that apply blockchain technology is increasing. The use of Hyperledger Fabric, a private blockchain, is on the rise to utilize blockchain technology in public firms and private firms. However, the newly emerging blockchain-based system is not sufficient to carry out auditing with existing audit check items, so it has no choice but to make and use audit items individually. Therefore, a need for verified audit items for systems that base on blockchain technology has emerged. In this study, we customized the Delphi process to derive audit items suitable for the system development project using the blockchain technology, and verified the completeness and accuracy of the audit items derived through a survey by the IS Auditor. This research will be of direct help to the IS Auditor, and it is expected that operators and organizers who provide services through the blockchain-based system will also contribute to improving the quality of the system.

• Journal of Information Processing Systems
• /
• v.16 no.2
• /
• pp.301-317
• /
• 2020

An enterprise patch-management system (PMS) typically supplies a single point of failure (SPOF) of centralization structure. However, a Blockchain system offers features of decentralization, transaction integrity, user certification, and a smart chaincode. This study proposes a Hyperledger Fabric Blockchain-based distributed patch-management system and verifies its technological feasibility through prototyping, so that all participating users can be protected from various threats. In particular, by adopting a private chain for patch file set management, it is designed as a Blockchain system that can enhance security, log management, latest status supervision and monitoring functions. In addition, it uses a Hyperledger Fabric that owns a practical Byzantine fault tolerant consensus algorithm, and implements the functions of upload patch file set, download patch file set, and audit patch file history, which are major features of PMS, as a smart contract (chaincode), and verified this operation. The distributed ledger structure of Blockchain-based PMS can be a solution for distributor and client authentication and forgery problems, SPOF problem, and distribution record reliability problem. It not only presents an alternative to dealing with central management server loads and failures, but it also provides a higher level of security and availability.

• International Journal of Computer Science & Network Security
• /
• v.23 no.10
• /
• pp.214-224
• /
• 2023

Fraudulence, cheating, and deception can occur in the commercial real estate (CRE) industry, besides the difficulty in searching for and transferring properties while ensuring the operation is processed through an authoritative source in a trusted manner. Nowadays, real estate transactions use neutral third parties to sell land. Indeed, properties can be sold by the owners or third parties multiple times or without a proper deed. Moreover, third parties request a large amount of money to mediate between the seller and buyer. Methods: We propose a new framework that uses a private blockchain network and predefined BPMN instances to enable the fast and easy recording of deeds and their proprietary transfer management controlled by the government. The blockchain allows for multiple verifications of transactions by permitted parties called peers. It promotes transparency, privacy, trust, and commercial competition. Results: We demonstrated the easy adoption of blockchain for land registration and transfer. The paper presents a prototype of the implemented product that follows the proposed framework. Conclusion: The use of Blockchain-based solutions to resolve the current land registration and transfer issues is promising and will contribute to smart cities and digital governance.

• Journal of Internet Computing and Services
• /
• v.20 no.6
• /
• pp.105-117
• /
• 2019

Bitcoin, which can be classified as a cryptocurrency, has attracted attention from various industries because it is an innovative digital currency and the beginning of a Blockchain system. However, as the research on Bitcoin progressed, several security vulnerabilities and possible attacks were analyzed. Among them, the security problem caused by the transparency of the Blockchain database prevents the Blockchain system from being applied to various fields. This vulnerability is further classified as the weak anonymity of participating nodes and privacy problem due to disclosure of transaction details. In recent years, several countermeasures have been developed against these vulnerabilities. In this paper, we first describe the main features of the public and private Blockchain, and explain privacy, unlinkability and anonymity. And, three public Blockchain platforms, Dash, Zcash and Monero which are derived from Bitcoin, and Hyperledger Fabric which is a private Blockchain platform, are examined. And we analyze the operating principles of the protocols applied on each platform. In addition, we classify the applied technologies into anonymity and privacy protection in detail, analyze the advantages and disadvantages, and compare the features and relative performance of the platforms based on the computational speed of the applied cryptographic mechanisms.

• Journal of the Korean Regional Science Association
• /
• v.37 no.2
• /
• pp.35-48
• /
• 2021

Modern cities are changing to 'smart cities' dramatically with the introduction and development of the fourth industrial revolution technologies. Among these technologies blockchain is unique because it not only embraces technological innovation but also societal revolution. Therefore, blockchain is expected to play a pivotal role for contributing comprehensive development of smart city. The current research and policy atmosphere in Korea, however, is that blockchain is just a new technology and its broader impacts are overlooked. This study argues that blockchain has significant effects on smart cities not only from technological perspectives but also from social, economic, institutional, governmental perspectives. Further, this study suggests three categories that blockchain can help the development of smart city: technology, socio-economic, and governance, with examples of existing blockchin projects. However, these projects have been builting separately without any interaction under the common hood of 'smart city'. To emhance influences of blockchain on smart cities in positive ways, private companies, policy maker, and citizend are supposed to consider and discuss about publi sector's blockchain that is commonly used in at the smart city level.

• International Journal of Computer Science & Network Security
• /
• v.22 no.12
• /
• pp.37-50
• /
• 2022

Modern supply chains include multiple activities from collecting raw materials to transferring final products. These activities involve many parties who share a huge amount of valuable data, which makes managing supply chain systems a challenging task. Current supply chain management (SCM) systems adopt digital technologies such as the Internet of Things (IoT) and blockchain for optimization purposes. Although these technologies can significantly enhance SCM systems, they have their own limitations that directly affect SCM systems. Security, performance, and scalability are essential components of SCM systems. Yet, confidentiality and scalability are one of blockchain's main limitations. Moreover, IoT devices are lightweight and have limited power and storage. These limitations should be considered when developing blockchain-based IoT-SCM systems. In this paper, the requirements of efficient supply chain systems are analyzed and the role of both IoT and blockchain technologies in providing each requirement are discussed. The limitations of blockchain and the challenges of IoT integration are investigated. The limitations of current literature in the same field are identified, and a secure and scalable blockchain-based IoT-SCM system is proposed. The proposed solution employs a Hyperledger fabric blockchain platform and tackles confidentiality by implementing private data collection to achieve confidentiality without decreasing performance. Moreover, the proposed framework integrates IoT data to stream live data without consuming its limited resources and implements a dualstorge model to support supply chain scalability. The proposed framework is evaluated in terms of security, throughput, and latency. The results demonstrate that the proposed framework maintains confidentiality, integrity, and availability of on-chain and off-chain supply chain data. It achieved better performance through 31.2% and 18% increases in read operation throughput and write operation throughput, respectively. Furthermore, it decreased the write operation latency by 83.3%.