• The Transactions of the Korea Information Processing Society
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• v.4 no.3
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• pp.659-669
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• 1997

Security as weel as consistency of data is very important issue in databaed security.This the serializability of transactions must be maintained and particularly covert channel not caesed between a high-level transaction and a low- level one.In this paper, we propose a secure transaction management algorithm using synamic version control] method that can slove disk space overhead to maintain multiversion and the problem that reansactions read too old versions when two versions are maintained.Disk space overhead can be sloved by properly cerating versions and synamically maintaining the number of versions and the problem for reading too old version can be solved by having transactions read versions as recent as possible.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.692-698
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• 2022

With the expansion of domestic hydrogen fuelling station infrastructure, it is necessary to secure reliability among hydrogen traders, and for this, technology to accurately measure hydrogen is important. In this study, 4 types of hydrogen trading volume calculation models (model 1-4) were presented to improve the accuracy of the hydrogen trading volume. In order to obtain the reference value of model 4, and experiment was conducted using a flow rate measurement equipment, and the error rate of the calculated value for each model was compared and analyzed. As a result, model 1 had the lowest metering accuracy, model 2 had the second highest metering accuracy and model 3 had the highest metering accuracy until a certain point. But after the point, model 2 had the highest metering accuracy and model 3 had the second metering accuracy.

• International Journal of Computer Science & Network Security
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• v.23 no.5
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• pp.128-134
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• 2023

The widespread usage of blockchain technology in cryptocurrencies has led to the adoption of the blockchain concept in data storage management systems for secure and effective data storage and management. Several innovative studies have proposed solutions that integrate blockchain with distributed databases. In this article, we review current blockchain databases, then focus on two well-known blockchain databases-BigchainDB and FalconDB-to illustrate their architecture and design aspects in more detail. BigchainDB is a distributed database that integrates blockchain properties to enhance immutability and decentralization as well as a high transaction rate, low latency, and accurate queries. Its architecture consists of three layers: the transaction layer, consensus layer, and data model layer. FalconDB, on the other hand, is a shared database that allows multiple clients to collaborate on the database securely and efficiently, even if they have limited resources. It has two layers: the authentication layer and the consensus layer, which are used with client requests and results. Finally, a comparison is made between the two blockchain databases, revealing that they share some characteristics such as immutability, low latency, permission, horizontal scalability, decentralization, and the same consensus protocol. However, they vary in terms of database type, concurrency mechanism, replication model, cost, and the usage of smart contracts.

• International Journal of Computer Science & Network Security
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• v.23 no.6
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• pp.91-98
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• 2023

The rapid increase in the use of new technology known as 'blockchain technologies' has addressed many challenges in different areas and provided benefits to users, in this paper we discuss the field of supply chains, improve confidence and transparency between participants and stakeholders significantly also in this paper we Compare between different blockchain frameworks focusing on most popular frameworks. Moreover, we proposed a model in the supply chain using a blockchain framework, the proposed supply chain model included many different resources that help to exchange information over the network. The proposed model also includes smart contracts that maintain all rules for transactions. using blockchain technology information such as transaction details, time and money are recorded and stored within the system from the beginning of the transaction entry.

• Journal of Software Assessment and Valuation
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• v.15 no.1
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• pp.115-121
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• 2019

I analyzed the structure of a block-chain system and a block-chain-based service system. It is a decentralized book encryption system software technology that does not require a third party to secure trust between the two parties. Block chains are structured in a linked list structure. The block chain manage transaction information by blocking the transaction information, in conjunction with other blocks. As a result, I have discovered structural weaknesses in current block-chain systems and block-chain-based service systems. Once these possible structural problems are resolved, I expect that the block-chain-based service system will make various industrial contributions.

• Asia pacific journal of information systems
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• v.30 no.1
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• pp.21-30
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• 2020

Bitcoin (BTC) is a type of cryptocurrency that supports transaction/payment of virtual money between BTC users without the presence of a central authority or any third party like bank. It uses some cryptographic techniques namely public- and private-keys, digital signature and cryptographic-hash functions, and they are used for making secure transactions and maintaining distributed public ledger called blockchain. In BTC system, each transaction signed by sender is broadcasted over the P2P (Peer-to-Peer) Bitcoin network and a set of such transactions collected over a period is hashed together with the previous block/other values to form a block known as candidate block, where the first block known as genesis-block was created independently. Before a candidate block to be the part of existing blockchain (chaining of blocks), a computation-intensive hard problem needs to be solved. A number of miners try to solve it and a winner earns some BTCs as inspiration. The miners have high computing and hardware resources, and they play key roles in BTC for blockchain formation. This paper mainly analyses the underlying cryptographic techniques, identifies some weaknesses and proposes their enhancements. For these, two modifications of BTC are suggested ― (i) All BTC users must use digital certificates for their authentication and (ii) Winning miner must give signature on the compressed data of a block for authentication of public blocks/blockchain.

• Advances in environmental research
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• v.12 no.2
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• pp.113-122
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• 2023

Biometric authentication has become an essential part of modern-day security systems, especially in financial institutions like banks. A face recognition-based ATM is a biometric authentication system, that uses facial recognition technology to verify the identity of bank account holders during ATM transactions. This technology offers a secure and convenient alternative to traditional ATM transactions that rely on PIN numbers for verification. The proposed system captures users' pictures and compares it with the stored image in the bank's database to authenticate the transaction. The technology also offers additional benefits such as reducing the risk of fraud and theft, as well as speeding up the transaction process. However, privacy and data security concerns remain, and it is important for the banking sector to instrument solid security actions to protect customers' personal information. The proposed system consists of two stages: the first stage captures the user's facial image using a camera and performs pre-processing, including face detection and alignment. In the second stage, machine learning algorithms compare the pre-processed image with the stored image in the database. The results demonstrate the feasibility and effectiveness of using face recognition for ATM authentication, which can enhance the security of ATMs and reduce the risk of fraud.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.299-306
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• 2015

In this paper, we research to secure stability of data storing/searching on NoSQL implemented on Distributed File System. When implementing NoSQL on Distributed File System, we faced that random write on Distributed File System is almost impossible. To solve this problem, a concept of Intermediate-File was employed, and then it has been achieved that our system resist any failure circumstance. Additionally, since we discovered its performance cannot be as fast as general File System, by redefining the file block unit for our NoSQL system, we have prevented a slowdown in system performance. As a result, we are able to develop highly scalable NoSQL as Distributed File System, which fulfills basic conditions of transaction: Atomicity, Consistency, Isolation, and Performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.8
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• pp.1701-1710
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• 2012

Recently, it has been found that it is important to use a smart grid to reduce greenhouse-gas emissions worldwide. A smart grid is a digitally enabled electrical grid that gathers, distributes, and acts on information regarding the behavior of all participants (suppliers and consumers) to improve the efficiency, importance, reliability, economics, and sustainability of electricity services. The smart grid technology uses two-way communication, where users can monitor and limit the electricity consumption of their home appliances in real time. Likewise, power companies can monitor and limit the electricity consumption of home appliances for stabilization of the electricity supply. However, if information regarding the measured electricity consumption of a user is leaked, serious privacy issues may arise, as such information may be used as a source of data mining of the electricity consumption patterns or life cycles of home residents. In this paper, we propose a data transaction protocol for privacy protection in a smart grid. In addition, a power company cannot decrypt an encrypted home appliance ID without the user's password.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.173-180
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• 2024

Along with its importance, the real estate market poses risks of various fraudulent activities. Recently, a surge in real estate-related scams, such as lease fraud, has caused great financial damage to many ordinary people. These problems are often caused by the complexity of real estate transactions and information imbalance. Therefore, there is an urgent need to secure reliability and improve transparency in the transaction process. In this paper, to solve this real estate fraud problem, we propose a chatbot system using digital technology and artificial intelligence, especially GPT (Generative Pre-Trained Transformer). This system serves to protect users from fraud by providing them with precautions and confirmations in the lease transaction process. In addition, GPT-based chatbots respond to questions from users in time, contributing to reducing uncertainty in the transaction process and increasing reliability.