• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.15 no.8
• /
• pp.2849-2864
• /
• 2021

The emerging of cloud data sharing can create great values, especially in multi-cloud environments. However, "data island" between different cloud service providers (CSPs) has drawn trust problem in data sharing, causing contradictions with the increasing sharing need of cloud data users. And how to ensure the data value for both data owner and data user before sharing, is another challenge limiting massive data sharing in the multi-cloud environments. To solve the problems above, we propose a Uniform Encoding and Parsing Framework (UEPF) with blockchain to support trustworthy and valuable data sharing. We design namespace-based unique identifier pair to support data description corresponding with data in multi-cloud, and build a blockchain-based data encoding protocol to manage the metadata with identifier pair in the blockchain ledger. To share data in multi-cloud, we build a data parsing protocol with smart contract to query and get the sharing cloud data efficiently. We also build identifier updating protocol to satisfy the dynamicity of data, and data check protocol to ensure the validity of data. Theoretical analysis and experiment results show that UEPF is pretty efficient.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.14 no.4
• /
• pp.17-26
• /
• 2018

Connected car plays an important role on Intelligent Transport System (ITS). ITS is able to secure drivers' convenience and safety, however, the overall system can be threatened by hacking attempt. Blockchain is one strong candidate of the remedy to promote the security of the ITS network. However, there will be many challenges to adopt previously proposed blockchain technologies to ITS. This work presents a new ITS structure based on blockchain technology. Proposed scheme includes three major layers. The first layer is central manager which is initiated once to register a certain connected car. The third layer is RSU (Road Side Unit) layer which exploits PoS (Proof of Stake) for consortium blockchains and retains real-time information. In addition, this layer performs block expiration based on timers to maintain manageable block length. In the second layer, the generated blocks of the third layer without expiration are housed as private blockchains. We finally demonstrate possible merits of newly proposed scheme.

• Journal of the Korean Society for information Management
• /
• v.38 no.3
• /
• pp.23-39
• /
• 2021

This study aims to explore research trends in Blockchain studies in South Korea using dynamic topic modeling and network analysis. To achieve this goal, we conducted the university & institute collaboration network analysis, the keyword co-occurrence network analysis, and times series topic analysis using dynamic topic modeling. Through the university & institute collaboration network analysis, we found major universities such as Soongsil University, Soonchunhyang University, Korea University, Korea Advanced Institute of Science and Technology (KAIST) and major institutes such as Ministry of National Defense, Korea Railroad Research Institute, Samil PricewaterhouseCoopers, Electronics and Telecommunications Research Institute that led collaborative research. Next, through the analysis of the keyword co-occurrence network, we found major research keywords including virtual assets (Cryptocurrency, Bitcoin, Ethereum, Virtual currency), blockchain technology (Distributed ledger, Distributed ledger technology), finance (Smart contract), and information security (Security, privacy, Personal information). Smart contracts showed the highest scores in all network centrality measures showing its importance in the field. Finally, through the time series topic analysis, we identified five major topics including blockchain technology, blockchain ecosystem, blockchain application 1 (trade, online voting, real estate), blockchain application 2 (food, tourism, distribution, media), and blockchain application 3 (economy, finance). Changes of topics were also investigated by exploring proportions of representative keywords for each topic. The study is the first of its kind to attempt to conduct university & institute collaboration networks analysis and dynamic topic modeling-based times series topic analysis for exploring research trends in Blockchain studies in South Korea. Our results can be used by government agencies, universities, and research institutes to develop effective strategies of promoting university & institutes collaboration and interdisciplinary research in the field.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.28 no.4
• /
• pp.987-997
• /
• 2018

Blockchain has tamper-free, so many applications are developing to leverage tamper-free features of blockchain. MIT Media Labs proposed BlockCerts, educational certificate blockchain System, to solve problems of legacy certificate verifications. Existing educational certificate blockchain Systems are based on public blockchain such as bitcoin, Ethereum, so any entity can participate educational institute in principal. Moreover, the exisitng educational certricate blockchain system utilizes the integrity of blockchain, but the confidentiality of the educational certificate is not provided. This paper propose a digital certificate system based on private blockchain, name HyperCerts. Therefore, only trusted entity can participate in the private blockchain network, Hyperledger, as the issuer of digital certificate. Furthermore, the practical byzantine fault tolerance is used as consensus algorithm, HyperCerts reduce dramatically the latency of issuing digital certificate and required computing power. HyperCerts stores the hash value of digital certificate into the ledger, so breach of personal information by malicious entity in the private blockchain is protected.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.5
• /
• pp.550-555
• /
• 2018

This study aims to identify and compare contents and keywords used in articles related to blockchain applications to various industries. The text mining and Semantic Network Analysis, as methods of keyword network analysis, were used to analyze articles including terms of 'finance' 'energy' and 'logistics', which media and government frequently mentioned as areas that can apply blockchain technologies. For this study, data were collected from 43,093 articles from January, 2017 through July, 2018. Data crawling was carried out by using Python BeautifulSoup and data cleaning was performed in order to eliminate mutual redundancies of the three terms. After that, text mining and semantic network analysis were performed using Textom and UCInet for network analysis between keywords. The results showed that all the three terms were similar in terms of 'technology', but there were differences in the contents of 'government policy' or 'industry' issues. In addition, there were differences in frequencies and centralities of these terms.

• The Korean Journal of Archival Studies
• /
• no.59
• /
• pp.47-78
• /
• 2019

With the rapid changes in the digital technology, it is necessary to shift to a new paradigm corresponding to the changing environment was recognized. This study actively explores the possibility of applying new technologies for recordkeeping. This study aimed to investigate the applicability of blockchain to recordkeeping and to develop a new model for recordkeeping based on it. Through a conceptual analysis of blockchain and consideration of the recordkeeping process, a blockchain model that is suitable for the authentication of records was proposed. For this the network structure, the structure of blockchain blocks, a consensus algorithm, and recordkeeping blockchain model were designed. It also predicted potential changes in digital records management when applying blockchain. It predicted change in governance aspects to implement a horizontal cooperation system among the archives.

• Journal of Platform Technology
• /
• v.9 no.1
• /
• pp.46-57
• /
• 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 Society of Computer and Information
• /
• v.26 no.12
• /
• pp.159-168
• /
• 2021

Building Information Modeling (BIM) data is a digitized construction design by worldwide construction design stands rules. Some research are being conducted to utilize blockchain for safe sharing and trade of BIM data, but there is no way to store BIM data directly in the blockchain due to the size of BIM data and technical limitation of the blockchain. In this paper, we propose a method of storing BIM data by combining a distributed file system and a blockchain. We propose two network overlays for storing BIM data, and we also propose generating the Level of Detail (LOD)-based merkle tree for efficient verification of BIM data. In addition, this paper proposes a system design for distributed storage of BIM data by using blockchain besu client and IPFS client. Our system design has a result that the processing speed stably increased despite the increase in data size.

• International Journal of Computer Science & Network Security
• /
• v.23 no.6
• /
• pp.17-26
• /
• 2023

Blockchain technology has emerged as one of the most crucial solutions in numerous industries, including healthcare. The combination of blockchain technology and cloud computing results in improving access to high-quality telemedicine and healthcare services. In addition to developments in healthcare, the operational strategy outlined in Vision 2030 is extremely essential to the improvement of the standard of healthcare in Saudi Arabia. The purpose of this survey is to give a thorough analysis of the current state of healthcare technologies that are based on blockchain and cloud computing. We highlight some of the unanswered research questions in this rapidly expanding area and provide some context for them. Furthermore, we demonstrate how blockchain technology can completely alter the medical field and keep health records private; how medical jobs can detect the most critical, dangerous errors with blockchain industries. As it contributes to develop concerns about data manipulation and allows for a new kind of secure data storage pattern to be implemented in healthcare especially in telemedicine fields is discussed diagrammatically.

• The Transactions of the Korea Information Processing Society
• /
• v.13 no.3
• /
• pp.102-110
• /
• 2024

Blockchain records all transactions issued by users, which are then replicated, stored, and shared by participants of the blockchain network. Therefore, the capacity of the ledger stored by participants continues to increase as the blockchain network operates. In order to address this issue, research is being conducted on methods that enhance storage efficiency while ensuring that valid values are stored in the ledger even in the presence of device failures or malicious participants. One direction of research is applying techniques such as Reed-Solomon encoding to the storage of blockchain ledgers. In this paper, we apply Reed-Solomon encoding to the key-value store used for ledger storage in an open-source blockchain, and measure the storage efficiency and increasing computational overhead. Experimental results confirm that storage efficiency increased by 86% while the increase in CPU operations required for encoding was only about 2.7%.