• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.647-656
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• 2020

Recently, there has been an increasing number of cases in which important data (personal information, technology, etc.) of national and public institutions are leaked to the outside world. Surveys show that the largest cause of such leakage accidents is "insiders." Insiders of organization with the most authority can cause more damage than technology leaks caused by external attacks due to the organization. This is due to the characteristics of insiders who have relatively easy access to the organization's major assets. This study aims to present an optimized property selection model for detecting such abnormalities through supervised learning algorithms among machine learning techniques using actual data such as CrossNet data transfer system transmission log, e-mail transmission log, and personnel information, which safely transmits data between separate areas (security area and non-security area) of the business network and the Internet network.

• The Journal of the Korea Contents Association
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• v.16 no.11
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• pp.139-153
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• 2016

Cyber incident collected from cyber-threat-intelligence sharing Center is growing rapidly due to expanding malicious code. It is difficult for Incident analysts to extract and classify similar features due to Cyber Attacks. To solve these problems the existing Similarity Analysis Method is based on single or multiple cyber observable of similar incidents from Cyber Attacks data mining. This method reduce the workload for the analysis but still has a problem with enhancing the unreality caused by the provision of improper and ambiguous information. We propose a incident analysis model performed similarity analysis on the hierarchically classified cyber observable based on cyber incident that can enhance both availability by the provision of proper information. Appling specific cyber incident analysis model, we will develop a system which will actually perform and verify our suggested model.

• Convergence Security Journal
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• v.11 no.6
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• pp.67-72
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• 2011

A system that provides a ubiquitous service is a networked system that has to overcome their circumstances that the service survivability is weak. the survivability of a networked system is defined as an ability of the system that can offer their services without interruption, regardless of whether components comprising the system are under failures, crashes, or physical attacks. This paper presents an approach that end users can obtain a quantitative evaluation of U-service survivability to reflect intended cyber attacks causing the networked system to fall into byzantine failures in addition to the definition of the survivability. In this paper, a Jini system based on wireless local area networks is used as an example for quantitative evaluation of U-service survivability. This paper also presents an continuous time markov chain (CTMC) Model for evaluation of survivability of U-service that a Jini system provides, and an approach to evaluate the survivability of the U-service as a blocking probability that end users can not access U-services.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.4
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• pp.16-22
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• 2012

In this paper, the forensic marking algorithm is proposed using psychoacoustic model II and MDCT for high-quality audio. The proposed forensic marking method, that inserts the user fingerprinting code of the audio content into the selected sub-band, in which audio signal energy is lower than the spectrum masking level. In the range of the one frame which has 2,048 samples for FFT of original audio signal, the audio forensic marking is processed in 3 sub-bands. According to the average attack of the fingerprinting codes, one frame's SNR is measured on 100% trace ratio of the collusion codes. When the lower strength 0.1 of the inserted fingerprinting code, SNR is 38.44dB. And in case, the added strength 0.5 of white gaussian noise, SNR is 19.09dB. As a result, it confirms that the proposed audio forensic marking algorithm is maintained the marking robustness of the fingerprinting code and the audio high-quality.

• Convergence Security Journal
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• v.17 no.4
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• pp.11-16
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• 2017

MANET composed of only mobile node is applied to various environments because of its advantage which can construct network quickly in emergency situation. However, many routing vulnerabilities are exposed due to the dynamic topology and link failures by the movement of nodes. It can significantly degrade network performance. In this paper, we propose a secure routing protocol based on trust model. The domain-based network structure is used for efficient trust evaluation and management of nodes in the proposed technique. The reliability evaluation of nodes was performed by the discard ratio of control packet and data packet of the nodes. The abnormal nodes are detected by performing traffic check and inspecting of nodes on a path that generates excessive traffic in order to increase the efficiency of routing. It is confirmed through experiments of the proposed technique that data transmission is performed securely even if an attack exists on the path.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.5
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• pp.127-136
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• 2018

In this paper, we propose a PIN entry method that combines with machine learning technique on smartphone. We use not only a PIN but also touch time intervals and locations as factors to identify whether the user is correct or not. In the user registration phase, a remote server was used to train/create a machine learning model using data that collected from end-user device (i.e. smartphone). In the user authentication phase, the pre-trained model and the saved PIN was used to decide the authentication success or failure. We examined that there is no big inconvenience to use this technique (FRR: 0%) and more secure than the previous PIN entry techniques (FAR : 0%), through usability and security experiments, as a result we could confirm that this technique can be used sufficiently. In addition, we examined that a security incident is unlikely to occur (FAR: 5%) even if the PIN is leaked through the shoulder surfing attack experiments.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.2 s.308
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• pp.81-92
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• 2006

This paper proposes a robustness watermarking for 3D mesh model based on projection onto convex sets (POCS). After designing the convex sets for robustness and invisibility among some requirements for watermarking system, a 3D-mesh model is projected alternatively onto two constraints convex sets until the convergence condition is satisfied. The robustness convex set are designed for embedding the watermark into the distance distribution of the vertices to robust against the attacks, such as mesh simplification, cropping, rotation, translation, scaling, and vertex randomization. The invisibility convex set are designed for the embedded watermark to be invisible. The decision values and index that the watermark was embedded with are used to extract the watermark without the original model. Experimental results verify that the watermarked mesh model has invisibility and robustness against the attacks, such as translation, scaling, mesh simplification, cropping, and vertex randomization.

• Convergence Security Journal
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• v.15 no.7
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• pp.31-38
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• 2015

Recently the government civil affairs administration system has been advanced to a cloud computing environment from a simple network environment. The electronic civil affairs processing environment in recent years means cloud computing environment based bid data services. Therefore, there exist lots of problems in processing big data for the government civil affairs service compared to the conventional information acquisition environment. That is, it processes new information through collecting required information from different information systems much further than the information service in conventional network environments. According to such an environment, applications of providing administration information for processing the big data have been becoming a major target of illegal attackers. The objectives of this study are to prevent illegal uses of the electronic civil affairs service based on IPs nationally located in civil affairs centers and to protect leaks of the important data retained in these centers. For achieving it, the safety, usability, and security of services are to be ensured by using different authentication processes and encryption methods based on these processes.

• Nuclear industry
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• v.37 no.8
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• pp.24-33
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• 2017

영화 '판도라'에 투입된 정도의 돈은 막대한 예산을 갖고 있는 국제 그린피스나 매년 전 세계 TV 광고에만 수천만 달러를 쏟아 붓는 천연가스 이익단체들의 예산에 비하면 조족지혈의 수준이다. 국제 그린피스의 연간 예산이 대략 4억 달러, EDF가 1억4천만 달러, 천연자원보호협회(NRDC)와 시에라클럽이 1억 달러가 넘고, 이들 단체가 예금이나 주식에 투자한 돈만 해도 수억 달러나 된다. 시에라클럽이나 NRDC, EDF는 블로그에 원자력을 화석연료로 대체하는 것에 반대하는 글을 올리면서 다른 한편으로는 뉴욕에 있는 Indian Point, 캘리포니아에 있는 Diablo Canyon, 그리고 오하이오에 있는 여러 원전들을 천연가스로 대체해야 한다고 주장하는 기만책을 쓰고 있다. 자연과의 조화를 위해서라도 신재생에너지를 사용해야 한다는 그들 주장의 베일 뒤에는 더 큰 어두운 그림자가 깔려 있다. 가난한 나라는 계속해서 가난하도록 해야 '과잉 인구'와 '과소비'를 막을 수 있다는 반인륜적인 멜더스(Malthusian) 이론과 그들이 주장하는 반핵의 오랜 역사는 서로 그 맥을 같이하고 있기 때문이다. 탈원전이 추진되면 전기요금도 올라가고 실업률도 증가한다는 사실, 그리고 환경 오염도 더 심해지고 그로 인해 조기 사망자 수도 증가한다는 사실을 보여주는 데 반드시 어려운 경제 모델이나 환경 모델이 필요한 것은 아니다. 원자력을 천연가스로 대체하면 그에 따른 비용 상승이 연간 최소 110억 달러나 된다. 물론 신재생에너지로 대체하게 되면 그 상승폭은 더욱 커지게 된다. 그리고 한 경제 분석 전문기관의 연구에 따르면 전기요금이 상승되면 한국의 경제는 저성장에서 벗어나지 못하게 된다. 결국 지금 우리에게 가장 필요한 것은 원자력 휴머니즘, 즉 원자력 에너지가 갖고 있는 훌륭한 도덕적인 목적을 다시 한 번 상기하면서, 우리 인류가 가지고 있는 가장 중요한 환경 기술을 반인륜적인 집단으로부터 구해내기 위한 풀뿌리 시민사회의 가열찬 노력이라고 할 수 있다. 우리와 같은 원자력 휴머니스트들에게는 그린피스나 기타 여러 반인륜적 집단들이 갖고 있는 풍부한 자원이 없다. 그러나 우리에게는 그런 종류의 자원이 필요한 것이 아니다. 우리에게는 그것보다 훨씬 더 중요한 진실이라는 자원이 있다는 사실을 결코 잊어서는 안될 것이다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.206-215
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• 2007

Ad-Hoc network technology is a mobile internet technology of the future that will be used widely not only in Mobile Network but also in Wireless Personal Area Network (WPAN) and Ubiquitous Network For this to occur, distributed routing protocol design, loop prevention for link information reduction in overhead for control messages and route restoration algorithm must be improved or complemented. Security techniques that can guarantee safe com-munication between Ad-Hot nodes net also be provided. This study proposes and evaluates a new authentication mechanism for MANET. The mechanism segregates the roles of certification authority to keep with the dynamic mobility of nodes and handle rapid and random topological changes with minimal over-head. That is, this model is characterized by its high expandability that allows the network to perform authentication service without the influence of joining and leaving nodes. The efficiency and security of this concept was evaluated through simulation.