• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.7
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• pp.2286-2304
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• 2022

Blockchain is a distributed ledger that combines technologies such as cryptography, consensus mechanism, peer-to-peer transmission, and time stamping. The rapid development of blockchain has attracted attention from all walks of life, but storage scalability issues have hindered the application of blockchain. In this paper, a scalable blockchain storage model based on Distributed Hash Table (DHT) and the InterPlanetary File System (IPFS) was proposed. This paper introduces the current research status of the scalable blockchain storage model, as well as the basic principles of DHT and the InterPlanetary File System. The model construction and workflow are explained in detail. At the same time, the DHT network construction mechanism, block heat identification mechanism, new node initialization mechanism, and block data read and write mechanism in the model are described in detail. Experimental results show that this model can reduce the storage burden of nodes, and at the same time, the blockchain network can accommodate more local blocks under the same block height.

• Convergence Security Journal
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• v.23 no.4
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• pp.17-22
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• 2023

Traditional authentication systems typically involve users entering their username and password into a centralized identity management system. To address the inconvenience of such authentication methods, a decentralized identity authentication system based on Distributed Identifiers(DID) is proposed, utilizing decentralized identity technology. The proposed system employs QR code scanning for login, enhancing security through the use of blockchain technology to ensure the uniqueness and safety of user identities during the login process. This system utilizes DIDs and integrates the InterPlanetary File System(IPFS) to securely manage organizational members' identity information while keeping it private. Using the distributed identity authentication system proposed in this study, it is possible to effectively manage the security and personal identity of organization members. To improve the usability of the system proposed in this study, research is needed to expand it into a solution.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.01a
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• pp.313-316
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• 2021

사물 인터넷 시스템에서 서버와 클라이언트의 신뢰성 확보는 매우 중요하다. 대부분의 IoT 시스템에서 신뢰성 확보를 위해 인증서 기법이 사용되고 있다. 인증서 기법을 사용하는 IoT 시스템은 데이터(인증서,공개키) 탈취 및 분실 취약점이 있다. 이러한 취약점을 강화하기 위해 서버와 클라이언트는 서로 주고받는 데이터의 무결성과 신뢰성을 보장할 수 있는 환경이 구축되어야 한다. 본 논문에서는 이러한 취약점을 보완하기 위하여 IPFS와 블록체인을 결합한 인증 강화 기법을 제시한다. 제시한 기법의 기본 개념은 IPFS를 이용하여 CA와 서버의 인증서와 공개키를 분산 저장하고, IPFS에 저장한 인증서와 공개키의 Content-Address를 블록체인에 보관한다. 마지막으로 제시한 기법의 타당성을 검토하기 위하여 Mobius, nCube, Ethereum, IPFS를 결합한 IoT 시스템을 구축하고 SSL을 사용한 인증 과정을 실험한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.11
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• pp.3694-3722
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• 2022

In today's globalized world, there is no transparency in exchanging data and information between producers and consumers. However, these tasks experience many challenges, such as administrative barriers, confidential data leakage, and extensive time delays. To overcome these challenges, we propose a decentralized, secured, and verified smart chain framework using Ethereum Smart Contract which employs Inter Planetary File Systems (IPFS) and MongoDB as storage systems to automate the process and exchange information into blocks using the Tendermint algorithm. The proposed work promotes complete traceability of the product, ensures data integrity and transparency in addition to providing security to their personal information using the Lelantos mode of shipping. The Tendermint algorithm helps to speed up the process of validating and authenticating the transaction quickly. More so in this time of pandemic, it is easier to meet the needs of customers through the Ethermint Smart Chain, which increases customer satisfaction, thus boosting their confidence. Moreover, Smart contracts help to exploit more international transaction services and provide an instant block time finality of around 5 sec using Ethermint. The paper concludes with a description of product storage and distribution adopting the Ethermint technique. The proposed system was executed based on the Ethereum-Tendermint Smart chain. Experiments were conducted on variable block sizes and the number of transactions. The experimental results indicate that the proposed system seems to perform better than existing blockchain-based systems. Two configuration files were used, the first one was to describe the storage part, including its topology. The second one was a modified file to include the test rounds that Caliper should execute, including the running time and the workload content. Our findings indicate this is a promising technology for food supply chain storage and distribution.

• Journal of Platform Technology
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• v.12 no.2
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• pp.45-57
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• 2024

Smart cities are the product of modern urban planning that seeks to innovate information and communication technology and improve the quality of urban life. For the efficient operation of smart cities, data collected, stored, and processed in real time is a key resource. Therefore, data from smart cities collected in various fields must be managed safely, and personal information protection is paramount. In this study, a smart city data security model using blockchain technology was proposed to safely manage smart city data. The proposed model integrates IPFS into the blockchain network to distribute and store data to ensure data confidentiality and integrity, and encrypts data using CP-ABE to efficiently control access to data from users. In addition, privacy was guaranteed while enhancing the usability of data by using Homomorphic Encryption with data access control policies.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.354-356
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• 2022

Profiles are the most basic means of representing who you are, and you represent yourself. In SNS and chatting apps that use profiles the most, profiles are used to express their experiences, moods, and thoughts. However, in voice phishing, impersonation crimes, etc., they steal and impersonate a photo such as a profile, and then deceive the victim into committing a crime. In this paper, to prevent the crime of impersonation, the authenticity of the original is determined using NFT that can distinguish the original. Minting the original profile picture with NFT, registering it on the blockchain network, and storing the original file in off-chain IPFS. This is expected to be effective in preventing impersonation crimes because it is possible to easily determine the authenticity of the profile picture.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.119-129
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• 2024

We look at Web 3.0 business model canvas (BMC) of metaverse gaming platform, The Sandbox (TS). As results, the decentralized, blockchain-based platform, TS benefits its creators and players by providing true ownership, tradability of decentralized assets, and interoperability. First, in terms of the governance and ownership, The SAND functions a governance token allowing holders to participate in decision and SAND owners can vote themselves or delegate voting rights to other players of their choice. Second, in terms of decentralized assets and activities, TS offers three products as assets like Vox Edit as a 3D tool for voxel ASSETS, Marketplace as NFT market, and Game Maker as a visual scripting toolbox. The ASSETS made in Vox Edit, sold on the Marketplace, can be also utilized with Game Maker. Third, in terms of the network technology, in-game items are no longer be confined to a narrow ecosystem. The ASSETS on the InterPlanetary File System (IPFS) are not changed without the owner's permission. LAND and SAND are supported on Polygon, so that users interact with their tokens in a single place. Last, in terms of the token economics, users can acquire in-game assets, upload these assets to the marketplace, use for paying transaction fees, and use these as governance token for supporting the foundation.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.149-160
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• 2024

For examining Web3.0 video streaming (VS) platforms in terms of the decentralized technology, tokenization and decentralized autonomous organization (DAO), we look at four platforms like DLive, DTube, Livepeer, and Theta Network (Theta). As a result, DLive which firstly partnered with Medianova for CDN and with Theta for peer to peer (P2P) network and migrates to Tron blockchain (BC), receives no commission from what creators earn, gives rewards to viewers by measuring engagement, and incentivizes participation by allowing 20% of donation & fees for funding development, 5% to BitTorrent Token (BTT) stakeholders (among these 5%, 20% to partners, 80% to other BTT stakeholders). DTube on its own lower-layer BC, Avalon, offers InterPlanetary File System (IPFS), gives 90% of the created value to creators or curators, and try to empower the community. Livepeer on Ethereum BC offers decentralized CDN, P2P, gives Livepeer Token (LPT) as incentive for network participants, and delegators can stake their LPT to orchestrators doing good. Theta on its native BC pulls streams from peering caching nodes, creates P2P network, gives Theta utility token, TFUEL for caching or relay nodes contributors, and allows Theta governance token, THETA as staking token. We contribute to the categorization of Web3.0 VS platforms: DLive and DTube reduce the risk of platform censorship, promote the diverse content, and allow the community to lead to more user-friendly environments. On the other hand, Livepeer and Theta provide new methods to stream content, but they have some differences. Whereas Livepeer focuses on the transcoding layer, Theta concentrates both on the video application layer and content delivery layer. It means, Theta tries to deliver value to all participants by enhancing network quality, reducing CDN cost, and rewarding users in utility tokens for the storage and bandwidth they provide.