• International journal of advanced smart convergence
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• v.9 no.2
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• pp.157-163
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• 2020

Recently the blockchain technology has been actively studied due to its great potentiality. The smart contract is a key mechanism of the blockchain system. Due to the short history of the smart contract, many issues have not been solved yet. One main issue is vulnerability and another main issue is cost optimization. While the vulnerability of smart contract has been actively studied, the cost optimization has been rarely studied. In this paper, we propose two cost optimization methods for smart contracts running on the blockchain system. Triggering a function in a smart contract program code may require costs and it is repeated continuously. So the minimization of costs required to trigger a function of smart contract while maintaining the performance equally is very important. The proposed two methods minimize the usage of expensive permanent variables deployed on the blockchain system. We apply the proposed two methods to three prevalent blockchain platforms: Ethereum, Klaytn and Tron. Evaluation experiments verify that the proposed scheme significantly reduces the costs of functions in the smart contract written with Solidity.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.189-195
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• 2020

Smart contract, one of the applications of blockchain, is expected to be used in various industries. However, there is risks of damages caused by attacks on vulnerabilities in smart contract codes. Tool support is essential to detect vulnerabilities, and as new vulnerabilities emerge and smart contract implementation languages increase, the tools must have extensibility for them. We propose a design model for extensible architecture of smart contract vulnerability detection tools that detect vulnerabilities in smart contract source codes. The proposed model is composed of design pattern-based structures that provides extensibility to easily support extension of detecting modules for new vulnerabilities and other implementation languages of smart contract. In the model, detecting modules are composed of independent module, so modifying or adding of module do not affect other modules and the system structure.

• Korea Trade Review
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• v.47 no.1
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• pp.163-180
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• 2022

The purpose of this study is to examine the extent to which smart contracts can be applied to the software export business and to find out the legislative issues to activate smart contracts. A smart contract is a computer program that automatically executes a contract when conditions are fulfilled. Smart contracts can play a pivotal role in the field that requires immediate execution of contract or in a highly standardized field with multiple parties involved. In the software export business, it is desirable to apply the smart contract partially rather than applying the smart contract to the entire process because various parties are involved and the process is very complicated. The business model of exporting packaged software, a completed software that is mainly licensed for use, rather than the business model of exporting customized software is suitable for using smart contracts because the project for implementing customized software is mainly focused in the development stage. When smart contracts are used in processes such as contract signing, payment, and project management, work efficiency can be increased. In addition, smart contracts can be used when conditions can be quantified, such as error penalties, in areas that previously required contracts with third parties such as banks, guarantors. In order for smart contracts to be actively used in practice, legal reviews on various issues are necessary including the legality of a smart contract and the validity as an electronic document of NFT (non-fungible token) certificate. Also, for the system stability preventing hacking, etc, the periodic verification or inspection by a third party is essential. To activate smart contracts in international transactions the international treaty regarding smart contracts is also necessary.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.2
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• pp.286-293
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• 2021

Smart contract based on the blockchain technology can be applied to the real estate registry including transactions. The Ethereum coin using multi layered protocol is widely accepted as the token for the smart contract. Block chain smart contract using SOLIDITY or PYTHON can mediate transactions auch as sale or lease, creating various scenarios in the property market. Those smart contract can construct the basis for the blockchain real estate registry, which is expected to overcome conventional transaction costs concerning the national law system, the asymmetric information and the currency exchange. The advantages of blockchain technology, namely security, decentralization, global transparency and openness can be applied to the smart contract system on the property registry. Several countries have advanced such blockchain real estate registry project recently, but no actual implementation has been reported for years, owing to institutional and technological impasses.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.235-237
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• 2018

The Internet has allowed many things to move fast, including sharing of data, files and others within a second. Many domains use applications range from IoT, smart cities, healthcare, and organizations to share the data when necessary. However, there are some challenges faced by existing systems that works on centralized nature. Such challenges are data breach, trustiness issue, unauthorized access and data fraud. Therefore in this work, we focus on using a smart contract which is used by blockchain platform and works on decentralized form. Furthermore, in this work our contract provides an access to the file uploaded onto the decentralized storage such as IPFS. By leveraging smart contract-role based which consist of a contract owner who can manage the users when access the certain resources such as a file and as well as use of decentralized storage to avoid single point of failure and censorship over secure communication channel. We checked the gas cost of the smart contract since most of contracts tends to be a high cost.

• Journal of the Korea Society of Computer and Information
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• v.25 no.1
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• pp.187-198
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• 2020

In this paper, We purpose an improvement plan for the settlement of smart contracts into legal norms through the recognition of the norms of blockchain-based smart contracts and the main influence factors on the norms of smart contracts. First, in terms of the normative necessity of smart contracts, legal protection against technical errors, government-level public relations education, and basic laws governing smart contract business are needed. Second, the contract norms will be accepted by the contract norms based on the blockchain designed to make the responsible material clear in terms of smart contract usability. Third, in terms of regulation of smart contracts, it can be seen that smart contracts are subsumed from existing laws or considering new legislation, but the norm of smart contracts cannot be prioritized over ease of use.

• Electronics and Telecommunications Trends
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• v.35 no.5
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• pp.134-138
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• 2020

Blockchain is an enabling technology for managing data with high trust and transparency among connected computers. Blockchain emerged with the advent of the Bitcoin cryptocurrency, and then, evolved as general-purpose platforms such as Ethereum, EOS, R3 Corda, and IBM Hyperledger Fabric. The application of blockchain covers a broad range of areas such as fintech, decentralized identity, distribution, real estate trading, games, and drone air traffic management. Smart contracts are indispensable for constructing blockchain services. This survey classifies smart contract languages by their features and shows their differences from existing general-purpose programming languages.

• Journal of Arbitration Studies
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• v.30 no.1
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• pp.87-111
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• 2020

Smart contracts are implemented by blockchain technology, which stores the terms of the contracts of both parties on the blockchain. In the event of an international dispute over smart contracts and blockchains, no special solution has been proposed, such as the enactment of the International Unification Act. The blockchain platform which operates smart contracts is decentralized and operates through distributed nodes around the world without central servers, making it difficult to establish jurisdiction and governing laws. As an alternative to traditional dispute-solving methods, a new mediation model-smart arbitration-is being attempted. The arbitration process is likely to be a preferred means of resolving disputes over smart contracts in practice. There are many problems, such as the fairness of the arbitration center on the selection and judgment of arbitrators, the question of securing reliability, the question of the validity of the arbitration agreement, and how much the court can be involved in the case. Preparations at the national level, such as fostering blockchains and smart contract experts, and overhauling the legal system, are needed.

• Korea Trade Review
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• v.48 no.3
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• pp.243-262
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• 2023

This study provides a systematic review of smart trade contracts, examining the research trends and theoretical background of utilizing smart contracts and blockchain technology for the digitalization and automation of trade contracts. Smart trade contracts are a concept that applies the automated contract system based on blockchain to trade-related transactions. The study analyzes the technical and legal challenges and proposes solutions. The technical aspect covers the development of smart contract platforms, scalability and performance improvements of blockchain networks, and security and privacy concerns. The legal aspect addresses the legal enforceability of smart contracts, automatic execution of contract conditions, and the responsibilities and obligations of contract parties. Smart trade contracts have been found to have applications in various industries such as international trade, supply chain management, finance, insurance, and energy, contributing to the ease of trade finance, efficiency of supply chains, and business model innovation. However, challenges remain in terms of legal regulations, interaction with existing legal frameworks, and technological aspects. Further research is needed, including empirical studies, business model innovation, resolution of legal issues, security and privacy considerations, standardization and collaboration, and user experience studies to address these challenges and explore additional aspects of smart trade contracts.

• Journal of KIBIM
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• v.11 no.1
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• pp.1-10
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• 2021

Blockchain is a secure technology that enables transactions between parties without risking data corruption. Besides cryptocurrencies, blockchain technology is being widely adopted in various forms by diverse industries. One promising application is construction contracts. Given that construction projects are executed under strict contractual requirements, blockchain technology-based contracts can ensure that contractual requirements are executed among parties to the contract. The objective of this study is to apply blockchain technology to smart construction contracts and determine their potential feasibility in construction management. In this study, a prototype smart construction contract is presented and its applicability is explored. We conclude that smart construction contracts can be effective as a contractual tool to enhance payment flows in the construction process.