• Review of KIISC
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• v.28 no.3
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• pp.33-37
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• 2018

암호 화폐가 다양해지면서 암호 화폐를 채굴하는 방법 또한 다양한 방향으로 생겨났다. CyptoNote라는 프로토콜을 이용한 암호 화폐 중 하나인 모네로를 채굴할 때 메모리를 중점적으로 사용하도록 되어 있다. Coinhive는 광고 없이 수익을 내기위한 방법으로 웹브라우저를 이용한 모네로를 채굴하는 API를 만들었다. 하지만 본래의 목적과 다르게 API를 악의적으로 사용하여 웹브라우저 방문자의 동의 없이 채굴하는 공격인 크립토재킹이 증가하게 되었다. 이러한 공격을 막기 위해 브라우저 확장 어플리케이션이 등장하였으나, 공격자는 이를 우회하기 위해 자바스크립트 난독화를 사용하고 있다. 본 논문에서는, 크립토재킹에 대한 연구동향을 분석하고자 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• fall
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• pp.310-313
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• 2021

최근 다양한 산업분야에서 디지털 사용자 트랜잭션의 보안성 강화와 디지털 자산의 거래 비용 최소화를 동시에 실현하기 위해 블록체인 기술을 점진적으로 확대하고 있다. 특히 무인 자동화 시스템으로의 전환이라는 과도기적 상황과 코로나-19 대유행이 맞물려 비대면 시장에 대한 관심이 커졌고, 비대면 시장의 수익 극대화와 안정적인 비대면 서비스 실현을 위해 블록체인 시스템과의 결합이 초점화되고 있다. 본 캡스톤디자인 보고서는 블록체인 기반 암호화폐 결제 서비스 애플리케이션을 설계하고 구현하는 과정을 기술한다. 특히 새로운 알트코인으로 평택코인과 관련된 앱 생태계 구축 과정, 그리고 평택코인 결제 서비스 지원 애플리케이션을 개발을 통한 스마트 암호화폐 결제 애플리케이션의 서비스 초기 모델 구현 과정에 대해 기술한다.

• Analyses & Alternatives
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• v.7 no.2
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• pp.147-178
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• 2023

While most of countries today are opposing the issuance of private-led cryptocurrency, nevertheless they are actively jumping into the issuance of government-led digital currency such as CBDC. This article aims to find an answer to this dual attitude of countries. To achieve the purpose, this article finds out the characteristics of political power and economic interest that digital currency has and applies it to the international dimension of the Bretton Woods II System. Then come up to the conclusion that the answer can be found in the fact that the current dual attitude of countries is closely related to the crisis of the international monetary order. The Bretton Woods II System, which led the world economy through reckless monetary expansion based on credit currency, exposed its limitations through the 2008 global financial crisis and put countries into difficulties. In this situation, the cryptocurrency, which appeared by raising the issue of the monopoly power of the central authority in issuing currency, had no choice but to act as an opportunity to drive countries further and further into a corner. This article views CBDC as a national response to address these issues. In other words, countries maintain their monetary power by absorbing the challenge of private digital currency at the government level through CBDC, and use this as a stepping stone to reorganize the international monetary order in crisis with the intention to use it as a means to their advantage. That is what this article is trying to argue.

• Journal of Intelligence and Information Systems
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• v.29 no.2
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• pp.129-148
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• 2023

Bitcoin is a blockchain technology-based digital currency that has been recognized as a representative cryptocurrency and a financial investment asset. Due to its highly volatile nature, Bitcoin has gained a lot of attention from investors and the public. Based on this popularity, numerous studies have been conducted on price and trend prediction using machine learning and deep learning. This study employed LSTM (Long Short Term Memory) and CNN (Convolutional Neural Networks), which have shown potential for predictive performance in the finance domain, to enhance the classification accuracy in Bitcoin price trend prediction. XAI(eXplainable Artificial Intelligence) techniques were applied to the predictive model to enhance its explainability and interpretability by providing a comprehensive explanation of the model. In the empirical experiment, CNN was applied to technical indicators and Google trend data to build a Bitcoin price trend prediction model, and the CNN model using both technical indicators and Google trend data clearly outperformed the other models using neural networks, SVM, and LSTM. Then SHAP(Shapley Additive exPlanations) was applied to the predictive model to obtain explanations about the output values. Important prediction drivers in input variables were extracted through global interpretation, and the interpretation of the predictive model's decision process for each instance was suggested through local interpretation. The results show that our proposed research framework demonstrates both improved classification accuracy and explainability by using CNN, Google trend data, and SHAP.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.3
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• pp.471-485
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• 2023

Recently, due to the nature of blockchain that guarantees users' anonymity, more and more cases are being exploited for crimes such as illegal transactions. However, cryptocurrency is protected in cryptocurrency wallets, making it difficult to recover criminal funds. Therefore, this study acquires artifacts from the data and memory area of a local PC based on user behavior from four browser extension wallets (Metamask, Binance, Phantom, and Kaikas) to track and retrieve cryptocurrencies used in crime, and analyzes how to use them from a digital forensics perspective. As a result of the analysis, the type of wallet and cryptocurrency used by the suspect was confirmed through the API name obtained from the browser's cache data, and the URL and wallet address used for the remittance transaction were obtained. We also identified Client IDs that could identify devices used in cookie data, and confirmed that mnemonic code could be obtained from memory. Additionally, we propose an algorithm to measure the persistence of obtainable mnemonic code and automate acquisition.

• Information Systems Review
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• v.21 no.1
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• pp.91-111
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• 2019

Around the end of 2017, the investment fever for cryptocurrencies-especially Bitcoin-has started all over the world. Especially, South Korea has been at the center of this phenomenon. Sinceit was difficult to find the profitable investment opportunities, people have started to see the cryptocurrency markets as an alternative investment objects. However, the cryptocurrency fever inSouth Korea is mostly based on psychological phenomenon due to expectation of short-term profits and social atmosphere rather than intrinsic value of the assets. Therefore, this study aimed to analyze influence of people's social sentiment on price movement of cryptocurrency. The data was collected for 181 days from Nov 1st, 2017 to Apr 30th, 2018, especially focusing on Bitcoin-related post in Twitter along with price of Bitcoin in Bithumb/UPbit. After the collected data was refined into neutral, positive and negative words through sentiment analysis, the refined neutral, positive, and negative words were put into regression model in order to find out the impacts of social sentiments on Bitcoin price. After examining the relationship by the regression analyses and Granger Causality tests, we found that the positive sentiments had a positive relationship with Bitcoin price, while the negative words had a negative relation with it. Also, the causality test results show that there exist two-way causalities between social sentiment and Bitcoin price movement. Therefore, we were able to conclude that the Bitcoin investors'behaviors are affected by the changes of social sentiments.

• Review of KIISC
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• v.28 no.4
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• pp.48-57
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• 2018

최근 국내외적으로 암호화폐 거래소(이하 '디지털 자산 거래소')를 대상으로 빈번히 발생하고 있는 암호화폐(이하 '디지털 자산') 탈취, 무단 입출금 등 보안 사고를 통하여 자금세탁 및 테러자금조성 등 사회적인 문제를 일으키는 불법 행위가 증가할 가능성이 높다. 본 논문에서는 국제 표준화 기구에서 다루고 있는 디지털 자산 거래소 보안에 관한 표준안, 국내외 법 규정 등을 분석하고 디지털 자산 거래 과정에서 발생할 수 있는 잠재적인 보안 위협을 식별함으로서 자금세탁 및 테러자금조성 방지를 위한 디지털 자산 거래 시스템의 개선 방안을 제시한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.210-213
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• 2016

최근 양자컴퓨터의 개발로 공개키 암호 방식이 풀릴 수 있어 양자암호에 대한 연구가 활발해 지고 있다. 본 논문에서는 지금까지 설명 된 양자암호의 개념과 양자키 분배 프로토콜에 대해 살펴보고, 더 나아가 양자암호 방식 이후의 포스트 양자암호 방식과 응용에 대해 살펴본다. 또한 화폐 위조 기술이 늘어나는 만큼 위조를 할 수 없는 양자 화폐에 대해 살펴본다. 이러한 양자암호에 대한 다방면의 연구는 기존의 공개키 암호 방식을 보완하거나 대체할 만한 강화되고 새로운 암호체계에 대한 연구의 좋은 시작이 될 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.360-362
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• 2017

올해 초, 구글(Google)이 SHA-1의 충돌 현상을 입증했다. 이것은 모든 타 암호 알고리즘 역시 안전할 수 없다는 것을 뜻하며, 향후 SHA-256을 사용하는 비트코인도 취약해질 수 있음을 의미한다. 이유인즉슨, 비트코인에서 사용되는 암호 및 해시 알고리즘은 답을 찾기 위해 상당한 시간이 소요되지만, 양자 컴퓨터의 큐비트를 바탕으로 하는 연산처리 능력은 그 시간을 대폭 감소시킬 수 있기 때문이다. 본 논문에서는 이와 같은 양자 컴퓨터가 비트코인에 얼마나 위협적일 수 있는지와 더불어 양자 컴퓨터 출현에 대비하고자 등장한 새로운 암호 화폐인 Byteball 및 QRL코인을 살펴보고자 한다.

• Korea Information Processing Society Review
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• v.29 no.4
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• pp.4-11
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• 2022