• Journal of the Korea Society of Computer and Information
• /
• v.27 no.6
• /
• pp.77-86
• /
• 2022

Recently, various cryptocurrencies (coins) based on block chains have appeared, and interest in privacy coins, which is an anonymity-based cryptocurrency that values personal information protection, is growing. In this paper, we look at coin abuse cases using privacy coins, and analyze the technology that guarantees the anonymity of 8 mainly traded privacy coins (Monero, Dash, Zcash, BEAM, Grin, Horizen, Verge, and Pirate Chain). We would like to analyze the applied technologies for We present the problems that can occur in these privacy coins, check the technology and each element applied to the privacy coin, and analyze the technical difficulty of the anonymity guarantee technology for the mainly traded coins through this, and Appropriate countermeasures and classification of privacy coins for technical difficulty were presented through the problem. Through this, the standard for re-evaluating the value of the coin according to the application of appropriate technology for the privacy coin can be presented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.569-570
• /
• 2017

Bitcoin-based blockchain technology provides an infrastructure that enables anonymous smart contracts, low-cost remittances, and online payments. However, the block-chain technology that implements the bitcoin has scalability constraints in tradeoffs between throughput and latency. To solve these problems, the Byzantine fault tolerant block-chain technique has been proposed. This technique improves throughput without increasing latency by selecting a leader and constructing many microblocks that do not contain proofs of work within the existing block by the leader. However, this technique may be less secure than existing techniques in selecting the reader. In this paper, we propose a technique for scalability of the blockchain technology by using microblock technology and parallel execution technique. Within one microblock there is information about several transactions. In the proposed scheme, the throughput of the microblocks can be increased by performing concurrently.

• Journal of Convergence for Information Technology
• /
• v.9 no.7
• /
• pp.14-24
• /
• 2019

It is necessary to look into multiple subjects, such as effectiveness, laws and polices of blockchain in order to easily accept blockchain technology in small and mid-sized enterprises(SME). This study analyzes the positive effects of applying the block chain to SMEs, examines the laws and policies required to apply them, and identifies the tasks. As a result, we confirmed that it can create positive effects such as optimizing supply chain management, simplifying import and export process documents, improving product quality, facilitating flow of funds, and improving transaction reliability. Also, we confirmed that it is necessary to improve the basic law of electronic transaction, electronic commerce law, electronic financial transaction law, personal information protection legislation, and needs policy supplement for platform development, education system for SMEs, transaction standardization guidelines, tax reduction policy, and block chain research and development. More extensive practical research and specific individual legal studies are needed in the future.

• Journal of the Korean Applied Science and Technology
• /
• v.18 no.2
• /
• pp.118-126
• /
• 2001

Micelle formation and adsorption at the $Ti0_{2}$ interface of a series of polystyrene-polythylene oxide(PS-PEO) block copolymer in aqueous solution was studied using fluorescence probing and small-angle X-ray methods. Further, the stability of aqueous $Ti0_{2}$ dispersion in the presence of copolymer was investigated by microelectrophoresis, optical density and sedimentation measurements. The dissolution of pyrene as fluorescent probe in aqueous surfactant solution leads to a slow decrease of the $I_{1}/I_{3}$ ratio, as the copolymer concentration increase; $I_{1}$ and $I_{3}$ are respectively the intensities of the first and third vibrionic peaks in the pyrene fluorescence emission. The behaviour was due to the characteristics of the copolymers and/or to the copolymer association efficiency in water. Moreover, the adsorption at the plateau level increases with decreasing PEO until chain length. The zeta potential of $TiO_{2}$ particles decreases with increasing copolymer concentration and reaches a plateau value. Finally, stabilization using block copolymers was more effective with samples having higher weight fractions of PS block.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.11
• /
• pp.139-146
• /
• 2020

Cloud computing technology provides economic and efficient system operation and management features to deal with rapidly changing IT technologies. However, this is less used in institutes and companies due to low security of cloud computing service. It is recognized that storing and managing important information, which is confidential in external systems is vulnerable to security threats. In order to enhance security of this cloud computing service, this paper suggests a system and user authentication reinforcement model. The suggested technology guarantees integrity of user authentication information and provides users with convenience by creating blocks for each cloud service and connecting service blocks with chains. The block chain user authentication model offers integrity assurance technology of block chains and system access convenience for SSO users. Even when a server providing cloud computing is invaded, this prevents chained invasions not to affect other systems.

• Journal of Internet of Things and Convergence
• /
• v.4 no.2
• /
• pp.13-20
• /
• 2018

In this paper, we propose an authentication system that combines 'Single-Sign-On' and 'Token-based authentication' based on 'Block Chain' technology. We provide 'access control' function and 'integrity' by combining block-chain technology with single-sign-on authentication method and provided stateless self-contained authentication function using Token based authentication method. It was able to enhance the security by performing the encryption based Token issuance and authentication process and provided convenience of authentication to Web Server. As a result, we can provide token-based SSO authentication service efficiently by providing a convenient way to improve the cumbersome authentication process.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.4
• /
• pp.759-764
• /
• 2021

Because sensitive and private information should be exchanged between electric vehicles and a V2G service provider, reliable communication channel is essential to operate Vehicle-to-Grid (V2G) system which considers battery of electric vehicles as a factor of smart grid. The block chain is a platform for cryptocurrency transaction and fully distributed database system running by only equivalent node in the network without help of any central management or 3^rd party. In this paper, the structure and operation method of the blockchain are investigated, and the application of the blockchain for the V2G system was also explained and analyzed.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.8
• /
• pp.2083-2100
• /
• 2023

The rise of Industry 5.0 has led to a smarter and more digital way of doing business, but with it comes the issue of user privacy and security. Only when privacy and security issues are addressed, will users be able to transact online with greater peace of mind. Thus, to address the security and privacy problems associated with industry blockchain technology, we propose a privacy protection scheme for online financial transactions based on verifiable ring signatures and blockchain by comparing and combining the unconditional anonymity provided by ring signatures with the high integrity provided by blockchain technology. Firstly, we present an algorithm for verifying ring signature based on distributed key generation, which can ensure the integrity of transaction data. Secondly, by using the block chain technique, we choose the proxy node to send the plaintext message into the block chain, and guarantee the security of the asset transaction. On this basis, the designed scheme is subjected to a security analysis to verify that it is completely anonymous, verifiable and unerasable. The protection of user privacy can be achieved while enabling online transactions. Finally, it is shown that the proposed method is more effective and practical than other similar solutions in performance assessment and simulation. It is proved that the scheme is a safe and efficient online financial transaction ring signature scheme.

• Advanced Industrial SCIence
• /
• v.2 no.2
• /
• pp.1-8
• /
• 2023

The goal of the study is to describe blockchain technology as it relates to enhancing supply chains in the retail sector in order to achieve sustainability. This study offers a critical analysis of the possible applications of blockchain technology and smart contracts to supply chain management. This paper explains how Blockchain technology may be used by customers and merchants in a variety of retail business operations to great advantage. By adopting a modified version of the UTUAT model, this study validates the possibility of using blockchain for supply chain management in the retail industry. The study found a significant and positive correlation between behavioral intention and acceptance toward employing block networks in supply chain management in the retail business. The behavior intention (BI) to adopt blockchain technology is significantly influenced by performance expectations, effect expectations, subjective standards, and enabling variables. The performance and effort expectations have a considerable impact on the BI to adopt blockchain in supply chain management.

• Journal of the Korea Convergence Society
• /
• v.9 no.7
• /
• pp.69-75
• /
• 2018

The key technology of Industry 4.0, Smart factory is evaluated as the driving force of our economic development hereafter and a lot of researches have been established. Various entities including devices, products and managers exist in smart factory, but roles of these entities may be continuous or variable and can become extinct not long after. Existing methods for access control are not suitable to adapt to the variable environment. If we don't consider certain security level, important industrial data can be the targets of attacks. We need a new access control method satisfying desired level of efficiency and security without excessive system loads. In this paper, we propose a new RBAC-PAC which extend AC defined for PKC to the authority attribute of roles. We distribute PACs for roles through block chain method to provide the efficient access control. We verified that RBAC-PAC is more efficient in the smart factory with large number of entities which need a frequent permission update.