• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권3호
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• pp.861-876
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• 2022

Cryptoassets such as Bitcoin and Ethereum are widely traded around the world. Cryptocurrencies are also transferred between investors. Cryptocurrency has become a new and attractive means of remittance. Thus, blockchain-based smart contracts also attract attention when central banks design digital currencies. However, it has been discovered that a significant amount of cryptoassets on blockchain are lost or stranded for a variety of reasons, including the loss of the private key or the owner's death. To address this issue, we propose a method for recoverable transactions that would replace the traditional transaction by allowing cryptoassets to be sent to a backup account address after a deadline has passed. We provide the computational workload required for our method by analyzing the prototype. The method proposed in this paper can be considered as a good model for digital currency design, including central bank digital currency (CBDC).

• 예술인문사회 융합 멀티미디어 논문지
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• 제9권9호
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• pp.819-831
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• 2019

현대에 거래되는 재화의 종류는 소비형태의 변화에 의해 급속도로 많아지고 있다. 그러나, 거래되는 재화의 종류가 많아진 만큼 이에 대한 정확한 가치판단이 흐려지는 경우가 발생한다. 미술품, 창작물 등의 재화는 소비자가 올바른 가치를 판단하기 어렵다는 단점이 크게 부각되고, 거래 형태 또한 다양하여 이에 대한 신뢰성을 보장받기 힘들다는 문제가 발생한다. 다양한 재화에 대한 접근성이 확대된 현재, 이러한 단점들은 공유경제 시장의 안정성을 저해하는 요인으로 꼽힌다. 본 논문에서는 이러한 문제점을 해결하기 위하여 신뢰성 있는 중개인을 통한 블록체인 기반의 재화 계약 서비스를 제안한다. 제안한 서비스는 이더리움 블록체인에서 동작하는 스마트 컨트랙트를 사용하여 신뢰성 있는 중개인을 등록하고 재화의 가치검증 및 계약 과정에 사용한다. 또한 재화의 등록 내용, 제안 및 계약 과정을 블록체인에 등록하여 계약 과정의 신뢰성을 보장한다. 모든 동작 과정은 스마트 컨트랙트에 등록되고, 이더리움 블록체인의 트랜잭션 히스토리에 저장되므로, 등록된 데이터의 신뢰성을 보장할 수 있다. 또한 등록, 제안 및 계약의 전 과정이 스테이트 머신 기반의 스마트 컨트랙트에 의해 동작하기 때문에 사용자는 계약 과정을 보다 안전하게 제어할 수 있다.

• Journal of Information Processing Systems
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• 제19권2호
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• pp.240-257
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• 2023

The industrial Internet of Things (IIoT) is characterized by intelligent connection, real-time data processing, collaborative monitoring, and automatic information processing. The heterogeneous IIoT devices require a high data rate, high reliability, high coverage, and low delay, thus posing a significant challenge to information security. High-performance edge and cloud servers are a good backup solution for IIoT devices with limited capabilities. However, privacy leakage and network attack cases may occur in heterogeneous IIoT environments. Cloud-based multi-party computing is a reliable privacy-protecting technology that encourages multiparty participation in joint computing without privacy disclosure. However, the default cloud selection method does not meet the heterogeneous IIoT requirements. The server can be dishonest, significantly increasing the probability of multi-party computation failure or inefficiency. This paper proposes a blockchain and smart contract-based optimized cloud node selection framework. Different participants choose the best server that meets their performance demands, considering the communication delay. Smart contracts provide a progressive request mechanism to increase participation. The simulation results show that our framework improves overall multi-party computing efficiency by up to 44.73%.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 춘계학술발표대회
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• pp.273-276
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• 2023

This paper presents the integration of Digital twin and Blockchain-based Supply Chain Management (DB-SCM) in a smart warehouse to create a more efficient, secure, and transparent facility. The process involves creating a digital twin of the warehouse using sensors and IoT devices and then integrating it with a blockchain-based supply chain management system to connect all stakeholders. All data are collected and tracked in real-time as goods move through the warehouse, and smart contracts are automatically executed to ensure accountability for all parties involved. The study also highlights the critical role of effective supply chain management in modern business operations and the significance of smart warehouses, which leverage advanced technologies such as robotics, AI, and data analytics to optimize warehouse operations. Later, we discuss the importance of digital twins, which allow for creating a virtual representation of a physical object or system, and their potential to revolutionize a wide range of industries. Therefore, DB-SCM offers numerous benefits, including enhanced efficiency, improved customer satisfaction, and increased sustainability, and provides a valuable case study for organizations seeking to optimize their supply chain operations.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.252-255
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• 2007

최근에 선진국에서 아주 빠른 시간(마이크로 초)에 작동이 되고, 크기가 소형이면서, 많은 케이블과 커넥터를 사용하지 않는 Smart Bus Controller(SCB) 기법을 이용한 초소형/초고속(스마트) 점화기술에 집중적인 연구를 진행하고 있는 실정이다. 이와 같은 점화기술은 기존의 점화장치에서 사용하던 케이블과 커넥터 공간을 최소화 할 수 있게 MEMS 기법을 이용하여 케이블과 커넥터 장치를 설계 제작하였고, 저 용량/저 전류에서 작동할 수 있는 플라즈마를 이용한 케이블과 커넥터 장치를 설계 제작하였고, 저 용량/저 전류에서 작동할 수 있는 플라즈마를 이용한 초고속 착화장치를 사용하여 전류와 전압(배터리) 크기와 용량도 많이 감소시킬 수 있다. 스마트 파이로테크닉스 점화장치 개발에는 간결한 회로 점화통제장치 설계 및 제작, 빠른 점화작동시간을 가능하게 하는 플라즈마형 초고속 착화장치 설계 및 특성연구가 필요하다. 본 연구에서는 플라즈마형 초고속 착화장치의 특성연구에 대해 기술하였다.

• International journal of advanced smart convergence
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• 제10권3호
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• pp.89-96
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• 2021

In various areas of the 4th industry, a big issue is software quality enhancement for stability and reliability of the smart software systems. After revising software promotion law at 2020, we must clearly define requirements and separate design parts and implementation parts of an all public software development contracts. In this study, we need to validate whether the final implementation of software is followed by the original design or not. To do this, we consider the design restoration through software visualization based on reverse engineering. Therefore we propose an UML design extraction and visualization method based on reverse engineering. Based on this, we may validate whether it is implemented according to the original design, and how much visualizes and includes the code the internal complexity for improvement of software quality.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2022년도 춘계학술발표대회
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• pp.272-275
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• 2022

The federated learning can be utilized in conjunction with the blockchain technology to provide good privacy protection and reward distribution mechanism in the field of intelligent IOT in edge computing scenarios. Nonetheless, the synchronous federated learning ignores the waiting delay due to the heterogeneity of edge devices (different computing power, communication bandwidth, and dataset size). Moreover, the potential of smart contracts was not fully explored to do some flexible design. This paper investigates the fusion application based on the FLchain, which is the combination of asynchronous federated learning and blockchain, discusses the communication optimization, and explores the feasible design of smart contract to solve some problems.

• 디지털융복합연구
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• 제18권4호
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• pp.237-242
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• 2020

온라인 상에서의 전자 상거래 관리 시스템은 점차 증가하고 있으며 다양한 항목에서 거래가 이루어지고 있다. 그러나 온라인 상에서의 중고 거래시 자동차와 같은 고액 거래에서는 판매자와 구매자 간의 신뢰성이 매우 중요하다. 그럼에도 불구하고, 기존의 중고 거래 시스템에서는 사기를 방지하거나 판매자를 신뢰할 수 있는 장치가 미흡하다. 본 논문은 중고 거래시 발생하는 신뢰성 향상을 위해 블록체인 기반의 중고 거래 관리 시스템을 개발하였다. 여러 분야의 중고 거래가 있지만 가장 금액이 큰 중고 자동차에 대한 거래 관리 시스템을 개발함으로써 안전 거래 시스템을 향상시켰다. 본 시스템은 이더리움 기반의 스마트 컨트랙트를 이용하여 제 3자의 개입 없이도 신뢰성을 보장하는 방식이다. 스마트 컨트랙트를 활용해서 중고자동차 거래에 필요한 계약을 설계하여 기존의 중고차 거래 시 거래 참가자의 노력과 시간을 감소시킴과 동시에 안전한 거래가 가능하도록 하였다. 그리고 본 시스템은 구매자와 판매자 간 정보의 비대칭성을 완화시키고 제 3자가 개입하지 않는 유통과정의 중개수수료를 절감 및 예방하였다.

• International Journal of Computer Science & Network Security
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• 제23권10호
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• pp.147-156
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• 2023

Electronic voting machines (EVMs) are replacing research ballots due to the errors involved in the manual counting process and the lengthy time required to count the votes. Even though these digital recording electronic systems are advancements, they are vulnerable to tampering and electoral fraud. The suspected vulnerabilities in EVMs are the possibility of tampering with the EVM's memory chip or replacing it with a fake one, their simplicity, which allows them to be tampered with without requiring much skill, and the possibility of double voting. The vote data is shared among all network devices, and peer-to-peer verification is performed to ensure the vote data's authenticity. To successfully tamper with the system, all of the data stored in the nodes must be changed. This improves the proposed system's efficiency and dependability. Elections and voting are fundamental components of a democratic system. Various attempts have been made to make modern elections more flexible by utilizing digital technologies. The fundamental characteristics of free and fair elections are intractability, immutability, transparency, and the privacy of the actors involved. This corresponds to a few of the many characteristics of blockchain-like decentralized ownership, such as chain immutability, anonymity, and distributed ledger. This working research attempts to conduct a comparative analysis of various blockchain technologies in development and propose a 'Blockchain-based Electronic Voting System' solution by weighing these technologies based on the need for the proposed solution. The primary goal of this research is to present a robust blockchain-based election mechanism that is not only reliable but also adaptable to current needs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권11호
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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.