• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.12
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• pp.4531-4544
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• 2021

Because the traditional network information security vulnerability risk assessment method does not set the weight, it is easy for security personnel to fail to evaluate the value of information security vulnerability risk according to the calculation value of network centrality, resulting in poor evaluation effect. Therefore, based on the network security data element feature system, this study designed a quantitative assessment method of network information security vulnerability detection risk under single transmission state. In the case of single transmission state, the multi-dimensional analysis of network information security vulnerability is carried out by using the analysis model. On this basis, the weight is set, and the intrinsic attribute value of information security vulnerability is quantified by using the qualitative method. In order to comprehensively evaluate information security vulnerability, the efficacy coefficient method is used to transform information security vulnerability associated risk, and the information security vulnerability risk value is obtained, so as to realize the quantitative evaluation of network information security vulnerability detection under single transmission state. The calculated values of network centrality of the traditional method and the proposed method are tested respectively, and the evaluation of the two methods is evaluated according to the calculated results. The experimental results show that the proposed method can be used to calculate the network centrality value in the complex information security vulnerability space network, and the output evaluation result has a high signal-to-noise ratio, and the evaluation effect is obviously better than the traditional method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.2
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• pp.498-514
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• 2012

Machine to machine (M2M) communications is the hottest issue in the standardization and industry area, it is also defined as machine-type communication (MTC) in release 10 of the 3rd Generation Partnership Project (3GPP). Recently, most research have focused on congestion control, sensing, computing, and controlling technologies and resource management etc., but there are few studies on security aspects. In this paper, we first introduce the threats that exist in M2M system and corresponding solutions according to 3GPP. In addition, we present several new security issues including group access authentication, multiparty authentication and data authentication, and propose corresponding solutions through modifying existing authentication protocols and cryptographic algorithms, such as group authentication and key agreement protocol used to solve group access authentication of M2M, proxy signature for M2M system to tackle authentication issue among multiple entities and aggregate signature used to resolve security of small data transmission in M2M communications.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.4
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• pp.69-78
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• 2008

We propose to analyze a weakness of quantum key distribution and quantum authentication which use entangled state were proposed by Bao-sen Shi(2001) and to improve the security of the protocol. The existing protocol had a weakness against an impersonation attack of an eavesdropper, because of a only process which authenticated a third party(Center) by users. In this paper, we propose improving the security of the protocol that authenticates users by a third party using check mode which applies CHSH inequality.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.1
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• pp.115-137
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• 2008

As stock market gets bigger, use of HTS(Home Trading System) is getting increased in stock exchange. HTS provides lots of functions such as inquiry about stock quotations, investment counsel and so on. Thus, despite the fact that the functions fur convenience and usefulness are developed and used, security functions for privacy and trade safety are insufficient. In this paper, we analyze the security system of HTS service through the key-logging and sniffing and suggest that many private information is unintentionally exposed. We also find out a vulnerable point of the system, and show the advisable criteria of secure HTS.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.2
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• pp.181-192
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• 2013

There have been various techniques to detect and control document leakage; however, most techniques concentrate on document leakage by outsiders. There are rare techniques to detect and monitor document leakage by insiders. In this study, we observe user's document reading behavior to detect and control document leakage by insiders. We make each user's document reading patterns from attributes gathered by a logger program running on Microsoft Word, and then we apply the proposed system to help determine whether a current user who is reading a document matches the true user. We expect that our system based on document reading behavior can effectively prevent document leakage.

• Journal of the Korea Society of Computer and Information
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• v.23 no.11
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• pp.75-84
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• 2018

Social engineering attack means to get information of Social engineering attack means to get information of opponent without technical attack or to induce opponent to provide information directly. In particular, social engineering does not approach opponents through technical attacks, so it is difficult to prevent all attacks with high-tech security equipment. Each company plans employee education and social training as a countermeasure to prevent social engineering. However, it is difficult for a security officer to obtain a practical education(training) effect, and it is also difficult to measure it visually. Therefore, to measure the social engineering threat, we use the results of social engineering training result to calculate the risk by system asset and propose a attack graph based probability. The security officer uses the results of social engineering training to analyze the security threats by asset and suggests a framework for quick security response. Through the framework presented in this paper, we measure the qualitative social engineering threats, collect system asset information, and calculate the asset risk to generate probability based attack graphs. As a result, the security officer can graphically monitor the degree of vulnerability of the asset's authority system, asset information and preferences along with social engineering training results. It aims to make it practical for companies to utilize as a key indicator for establishing a systematic security strategy in the enterprise.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.318-321
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• 2006

현재 국내 국책사업으로 추진 중인 와이브로(WiBro) 기술 규격이 포함되어 있는 휴대인터넷 표준 규격인 IEEE 802.16e는 IP기반으로, 이동성이 뛰어나고 고속전송 기능의 특징을 가지고 있다. 또한 기지국간의 핸드오버(Handover)를 지원함으로써 이동성을 지원한다. 그러나 이러한 핸드오버 기법에 있어서 Replay 공격, Man-in-the-Middle 공격, Stolen-Verifier 공격 등에 취약한 문제점이 드러나고 있다. 본 논문은 이러한 기존 핸드오버 기법의 취약점을 개선하기 위해서 사용자의 인증서와 Timestamp값을 통한 IEEE 802.16e/와이브로 망에서 안전한 핸드오버 적용 방안에 대해 제안한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.511-514
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• 2006

ABCD는 FGCS'2004에 이장두 등에 의하여 제안된 블록 암호이다. ABCD는 256비트의 평문을 입력받아 128비트의 키를 사용하여 256비트의 암호문을 출력하는 블록암호이다. ABCD는 지금가지 분석 결과가 알려져 있지 않으며, 본 논문에서는 $7{\times}2^{8}$의 선택 평문을 이용하여, 공격복잡도 $2^{54}$을 갖는 전체 라운드 포화공격을 소개한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.707-711
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• 2006

암호화 문서 검색 시스템은 사용자의 비밀키를 이용하여 데이터베이스 서버에 저장되어 있는 암호화 문서를 키워드를 이용하여 검색하는 시스템이다. 이러한 시스템은 데이터베이스 서버 관리자조차도 사용자들에 의해 저장되고 검색되는 문서에 대한 어떠한 정보도 노출시키지 않는 장점이 있다. 즉, 암호화 문서 검색 시스템은 일반 사용자들이 자신의 정보가 손쉽게 노출되는 것을 원치 않는 사회적 변화에 발맞추어 앞으로 지속적으로 발전할 수 있는 연구 주제이다. 하지만, 지금까지 제안된 대부분의 기법들은 이론적인 안전성에만 치우친 나머지 현실적인 적용 가능성이 고려되지 않았다. 이에 본 연구에서는 기존에 제안된 대표적인 기법들을 현실 상황에 맞게 구현하여 검색 시스템의 효율성에 대해 판단한다. 더불어 해당 결과를 바탕으로 앞으로 암호화된 검색 시스템이 나아가야 할 방향을 제시한다.

• Annual Conference of KIPS
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• 2015.10a
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• pp.602-605
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• 2015

정보통신의 발달로 인해 우리의 삶을 풍요롭게 해주는 기술들이 많이 생겨났다. 그러나 기술의 발전을 악의적인 목적으로 사용하는 이들이 타인의 정보를 탈취하기 위한 도구를 만들었고, 키로거 역시 그러한 목적을 달성하기 위한 도구 중 하나로 이용되고 있다. 이에 본 논문에서는 기존의 키로거를 소프트웨어 기반과 하드웨어 기반 키로거로 분류한 뒤 하드웨어 키로거의 특징을 언급한다. 그리고 마지막으로 기존의 탐지방법으로 탐지되지 않는 하드웨어 기반의 키로거의 탐지방법에 대해 설명한다.