• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1159-1162
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• 2002

네트워크 기반의 IDS(Intrusion Detection System)가 개발된 이후 네트워크 패킷 정보를 분석하여 침입을 탐지하는 방법들이 연구되고 있다. 그러나 네트워크의 규모가 커지면서 NIDS 에서 발생하는 이벤트의 양이 증가하고 거짓 이벤트의 양도 따라 증가함으로써 이를 분석하는데 어려움이 있다. 본 논문은 많은 이벤트로부터 보다 위험성 있는 공격을 탐지하는 방법을 제시하고, 이를 현재 사용되고 있는 NIDS인 snort에 확장시켜 구현 하였다. 본 시스템은 침입자의 의도파악을 위하여 스캔과 같은 기본적인 이벤트를 관리한다. 또한 새로운 취약점에 대한 공격에 우선순위를 두어 오래된 공격방법보다 최근의 공격방법에 더 높은 우선순위를 부여한다. 전체 request 에서 공격이라 판단되는 request의 비율로써 사용자가 공격의도가 있는지를 파악한다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.476-479
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• 2010

In recent years, the deterioration of infrastructures is especially considered. In prestress concrete bridges, one of the important mechanisms of deterioration is the corrosion of the post-tensioned tendon due to environmental agents. In this study, the reliability analysis is performed for a prestress concrete box girder bridge under the pitting corrosion attack with considering the inspection and failure cost. The variation of life-time performance depending on inspection methods have to be quantified. The inspection methods with different accuracy of corrosion detection are presented and applied for model of reliability analysis. The computer program for analysis reliability index of the structure as well as updating process is obtained. An existing bridge is applied for illustrating the influence of inspection cost on the behaviors of structure. Subsequently, the benefit of inspection has shown to predict the time to failure of structure.

• Journal of Convergence Society for SMB
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• v.4 no.4
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• pp.31-36
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• 2014

Recent advancement in Wireless Sensor Networks (WSNs) has paved the way for WSNs to enable in various environments in monitoring temperature, motion, sound, and vibration. These applications often include the detection of sensitive information from enemy movements in hostile areas or in locations of personnel in buildings. Due to characteristics of WSNs and dealing with sensitive information, wireless sensor nodes tend to be exposed to the enemy or in a hazard area, and security is a major concern in WSNs. Because WSNs pose unique challenges, traditional security techniques used in conventional networks cannot be applied directly, many researchers have developed various security protocols to fit into WSNs. To develop countermeasures of various attacks in WSNs, descriptions and analysis of current security attacks in the network layers must be developed by using a standard notation. However, there is no research paper describing and analyzing security models in WSNs by using a standard notation such as The Unified Modeling Language (UML). Using the UML helps security developers to understand security attacks and design secure WSNs. In this research, we provide standard models for security attacks by UML Sequence Diagrams to describe and analyze possible attacks in the three network layers.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.3
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• pp.491-498
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• 2014

Recently, cyber terror has been occurred frequently based on advanced persistent threat(APT) and it is very difficult to detect these attacks because of new malwares which cannot be detected by anti-virus softwares. This paper proposes and verifies the algorithms to detect the advanced persistent threat previously through real-time network monitoring and combinatorial analysis of big data log. In the future, APT attacks can be detected more easily by enhancing these algorithms and adapting big data platform.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.848-851
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• 2005

The BcN is applying from public networks to local networks and each terminal step by step until 2007. By IPv6 network introduction, IP address lack problem can be solved. However, the threats that network attacks of another method can be caused with new problem of network security in IPv6 networks. In this paper, we suggest the traffic analysis tool which analyze IPv6 traffic efficiently to detect/response network attack in IPv6 environment. The implemented IPv6 traffic analysis tool uses IPv6 header to analyze traffic and detect network attacks. Also, we also propose detection algorithm to detect network attacks in IPv6 networks.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.166-169
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• 2018

캐시 부채널 공격 중 하나인 FLUSH+RELOAD 공격은 높은 해상도와 적은 오류로 그 위험성이 높고, 여러가지 프로그램에서도 적용되어 개인정보의 유출에 대한 위험성까지 증명 되었다. 따라서 이 공격을 막기 위해 실시간으로 감지 할 수 있어야 할 필요성이 있다. 본 연구에서는 4가지 실험을 통하여 이 FLUSH+RELOAD 공격을 받을 때 PCM(Performance Counter Monitor)를 사용해 각각의 counter들의 값의 변화를 관찰하여 3가지 중요한 요인에 의해 공격 탐지를 할 수 있다는 것을 발견하였다. 이를 이용하여 머신 러닝의 logistic regression과 ANN(Artificial Neural Network)를 사용해 결과에 대한 각각 학습을 시킨 뒤, 실시간으로 공격에 대한 탐지를 할 수 있는 프로그램을 제작하였다. 일정한 시간동안 공격을 진행하여 모든 공격을 감지하는데 성공하였고, 상대적으로 적은 오탐률을 보여주었다.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.989-998
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• 2019

Autophagy is crucial for immune defense against Mycobacterium tuberculosis (Mtb) infection. Mtb can evade host immune attack and survival within macrophages by manipulating the autophagic process. MicroRNAs (miRNAs) are small, non-coding RNAs that are involved in regulating vital genes during Mtb infection. The precise role of miRNAs in autophagy with the exits of Mtb remains largely unknown. In this study, we found miR-1958, a new miRNA that could regulate autophagy by interacting with 3'UTR of autophagy-related gene 5 (Atg5). In addition, Mtb infection triggered miR-1958 expression in RAW264.7 cells. What's more, miR-1958 overexpression blocked autophagic flux by impairing the fusion of autophagosomes and lysosomes. Overexpression of miR-1958 reduced Atg5 expression and LC3 puncta while inhibition of miR-1958 brought an increase of Atg5 and LC3 puncta; the opposite results were observed in detection of p62. The survival of Mtb in RAW264.7 cells transfected with mimic of miR-1958 was enhanced. Taken together, our research demonstrated that a novel miR-1958 could inhibit autophagy by interacting with Atg5 and favored intracellular Mtb survival in RAW264.7 cells.

• Convergence Security Journal
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• v.19 no.1
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• pp.87-95
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• 2019

The damage is increasing due to many encroachment accidents caused by increasingly sophisticated cyber attacks. Many institutions and businesses lack early response to invest a lot of resources in the infrastructure for incident detection. The initial response of an intrusion is to identify the route of attack, and many cyber attacks are targeted at software vulnerabilities. Therefore, analyzing the artifacts of a Windows system against software vulnerabilities and classifying the analyzed data can be utilized for rapid initial response. Therefore, the remaining artifacts upon entry of attacks by software are classified, and artifact grouping is presented for use in analysis of encroachment accidents.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.2
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• pp.75-84
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• 2008

Recently, the straightforward CRT-RSA was shown to be broken by fault attacks through many experimental results. In this paper, we analyze the fault attacks against CRT-RSA and their countermeasures, and then propose a new fault infective method resistant to the various fault attacks on CRT-RSA. In our CRT-RSA algorithm, if an error is injected in exponentiation with modulo p or q, then the error is spreaded by fault infective computation in CRT recombination operation. Our countermeasure doesn't have extra error detection procedure based on decision tests and doesn't use public parameter such as e. Also, the computational cost is effective compared to the previous secure countermeasures.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1871-1890
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• 2021

The transition toward a contactless society has been rapidly progressing owing to the recent COVID-19 pandemic. As a result, the IT environment of organizations and enterprises is changing rapidly; in particular, data security is expanding to the private sector. To adapt to these changes, organizations and companies have started to securely transfer confidential data to residential PCs and personally owned devices of employees working from home or from other locations. Therefore, organizations and companies are introducing streaming data services, such as the virtual desktop infrastructure (VDI) or cloud services, to securely connect internal and external networks. These methods have the advantage of providing data without the need to download to a third terminal; however, while the data are being streamed, attacks such as screen shooting or capturing are performed. Therefore, there is an increasing interest in prevention techniques against screen capture threats that may occur in a contactless environment. In this study, we analyze possible screen capture methods in a PC and a mobile phone environment and present techniques that can protect the screens against specific attack methods. The detection and defense for screen capture of PC applications on Windows OS and Mac OS could be solved with a single agent using our proposed techniques. Screen capture of mobile devices can be prevented by applying our proposed techniques on Android and iOS.