• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.715-729
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• 2021

Bitcoin is one of the cryptocurrencies, which is decentralized and transparent. However, due to its anonymity, it is currently being used for the purpose of transferring funds for illegal transactions in darknet markets. To solve this problem, clustering heuristic based on the characteristics of a Bitcoin transaction has been proposed. However, we found that the previous heuristis suffer from high false negative rates. In this study, we propose a novel heuristic for bitcoin clustering using off-chain data. Specifically, we collected and analyzed user review data from Silk Road 4 as off-chain data. As a result, 31.68% of the review data matched the actual Bitcoin transaction, and false negatives were reduced by 91.7% in the proposed method.

• Convergence Security Journal
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• v.23 no.4
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• pp.33-41
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• 2023

In recent years, advanced persistent threat (APT) attack organizations have exploited various vulnerabilities and attack techniques to target companies and institutions with national core technologies, distributing ransomware and demanding payment, stealing nationally important industrial secrets and distributing them on the black market (dark web), selling them to third countries, or using them to close the technology gap, requiring national-level security preparations. In this paper, we analyze the attack methods of attack organizations such as Kimsuky and Lazarus that caused industrial secrets leakage damage through APT attacks in Korea using the MITRE ATT&CK framework, and derive 26 cybersecurity-related administrative, physical, and technical security requirements that a company's security system should be equipped with. We also proposed a security framework and system configuration plan to utilize the security requirements in actual field. The security requirements presented in this paper provide practical methods and frameworks for security system developers and operators to utilize in security work to prevent leakage of corporate industrial secrets. In the future, it is necessary to analyze the advanced and intelligent attacks of various APT attack groups based on this paper and further research on related security measures.