• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1105-1114
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• 2021

Due to the recent surge in popularity of cryptocurrency, the threat of cryptojacking, a malicious code for mining cryptocurrencies, is increasing. In particular, web-based cryptojacking is easy to attack because the victim can mine cryptocurrencies using the victim's PC resources just by accessing the website and simply adding mining scripts. The cryptojacking attack causes poor performance and malfunction. It can also cause hardware failure due to overheating and aging caused by mining. Cryptojacking is difficult for victims to recognize the damage, so research is needed to efficiently detect and block cryptojacking. In this work, we take representative distinct symptoms of cryptojacking as an indicator and propose a new architecture. We utilized the K-Nearst Neighbors(KNN) model, which trained computer performance indicators as behavior-based dynamic analysis techniques. In addition, a K-means model, which trained the frequency of malicious script words for script similarity-based static analysis techniques, was utilized. The KNN model had 99.6% accuracy, and the K-means model had a silhouette coefficient of 0.61 for normal clusters.

• Journal of Intelligence and Information Systems
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• v.13 no.3
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• pp.119-140
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• 2007

Recommender systems enable a user to decide which information is interesting and valuable in our world of information overload. As the recent studies of distributed computing environment have been progressing actively, recommender systems, most of which were centralized, have changed toward a peer-to-peer approach. Collaborative Filtering (CF), one of the most successful technologies in recommender systems, presents several limitations, namely sparsity, scalability, cold start, and the shilling problem, in spite of its popularity. The move from centralized systems to distributed approaches can partially improve the issues; distrust of recommendation and abuses of personal information. However, distributed systems can be vulnerable to attackers, who may inject biased profiles to force systems to adapt their objectives. In this paper, we consider both effective CF in P2P environment in order to improve overall performance of system and efficient solution of the problems related to abuses of personal data and attacks of malicious users. To deal with these issues, we propose a multi-agent framework for a distributed CF focusing on the trust relationships between individuals, i.e. web of trust. We employ an agent-based approach to improve the efficiency of distributed computing and propagate trust information among users with effect. The experimental evaluation shows that the proposed method brings significant improvement in terms of the distributed computing of similarity model building and the robustness of system against malicious attacks. Finally, we are planning to study trust propagation mechanisms by taking trust decay problem into consideration.

• Journal of KIISE:Databases
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• v.37 no.5
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• pp.258-266
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• 2010

In this paper, we introduce a novel method to predict next update of blogs. The number of RSS feeds registered on meta-blogs is on the order of several million. Checking for updates is very time consuming and imposes a heavy burden on network resources. Since blog search engine has limited resources, there is a fix number of blogs that it can visit on a day. Nevertheless we need to maximize chances of getting new data, and the proposed method which predicts update probability on blogs could bring better chances for it. Also this work is important to avoid distributed denial-of-service attack for the owners of blogs. Furthermore, for the internet as whole this work is important, too, because our approach could minimize traffic. In this study, we assumed that there is a specific pattern to when a blogger is actively posting, in terms of days of the week and, more specifically, hours of the day. We analyzed 15,119 blogs to determine a blogger's posting preference. This paper proposes a method to predict the update probability based on a blogger's posting history and preferred days of the week. We applied proposed method to 12,115 blogs to check the precision of our predictions. The evaluation shows that the model has a precision of 0.5 for over 93.06% of the blogs examined.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1428-1438
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• 2013

Services take place in Internet environment, a formation of the trust relationship between user and service provider for services. Different authentication schemes such as using Certificate of Public Key Infrastructure authentication and using ID/PW for a simple user authentication have been proposed for trust relationship. In addition, in the case of electronic financial transactions, transaction integrity and non-repudiation features are provided. These services are provided in Internet environment, use various measures to ensure service safety. However, it was difficult to prevent attacks using existing security technology because of emergence of MITB attack that manipulate the memory area of the Web browser and social engineering attacks such as phishing/pharming, requires application of new security technologies became. In this paper, we propose a concept of smart secure-pad, and utilize it safely formed a trust relationship between user and service provider, a model has been proposed to ensure safety of data transmission. Proposed model's security evaluation results show security against to MITB attack and phishing/pharming that can't be prevent attack using existing security technology. In addition, service provider can easily apply the model in safe environment can provide Internet service using provided representative services applying the proposed model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.668-677
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• 2012

This study analyzed the related factors affecting to perceived gastritis or perceived enteritis for 11,753 Korean high school seniors who participated in the 2009 Korea Youth Risk Behavior Web-based Survey (KYHRBWS). Of the subjects, 5,685 (47.6%)were male and 6,068(52.4%) were female and 8.7% of the students responded that they had suffered from gastritis or enteritis for a long time and the females had a slightly higher attack rate of gastritis or enteritis. Survey logistic regression models and decision tree analysis were used to calculate odd ratios and 95% confidence intervals. As a result, there was affecting to their stress and health behaviors in the risk of gastritis and enteritis, and that their lower level perceived health, smoking, heavy drinking or starting drinking before they were 13 years old and a higher level of perceived stress significantly affected the risk of gastritis or enteritis in the subjects(p<.001).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.61-71
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• 2017

ARP Spoofing is a basic and core hacking technology for almost all sniffing. It makes change the flow of packets by faking the 2nd layer MAC address. In this paper we suggested an efficient hacking technology for sniffing remote servers in the switched network environment. The suggested 'Faked ARP Reply Unicast Spoofing' makes the bidirectional packets sniffing possible between the client and server, and it makes simplify the procedures for ARP sniffing and hacking program. In this paper we researched the network hacking and implementation technologies based on the suggested ARP spoofing. And we researched various types of servers hacking such as Root ID and PW of Telnet/FTP server, Root ID and PW of MySQL DB server, ID and PW of Web Portal Server, and account information and transaction history of Web Banking Server. And also we researched the implementation techniques of core hacking programs for the ARP Spoofing.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.5
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• pp.352-365
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• 2012

A primary study on the rapid modeling of storm surge, which is one of typical coastal disasters, for immediate forecasting in conjunction with typhoon advisories is done and tested for the typhoons Bolaven, Tembin and Sanba which attacked to Korean Peninsula on August and September in this year 2012. Semi automatic rapid computations according to JTWC typhoon advisories were performed and uploaded to the web by models SLOSH in PC and ADCIRC in parallel clusters with 64 cores having 57k nodes encompassing the North-Western Pacific region. It only takes 1 and 2 hours from taking advisory to web uploading, respectively. By comparison with observed water surface elevations for the major tidal stations after Bolaven attack it shows within RMS error of 0.17~0.19 m for surge heights and only deviates 1 hour of peak surge time in ADCIRC model. Thus it is concluded that this approach provides a frame of near real-time immediate forecasting of storm surges with satisfactions.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.6
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• pp.1343-1354
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• 2018

OAuth 2.0 bearer token and JWT(JSON web token), current standard technologies for authentication and authorization, use the approach of sending fixed token repeatedly to server for authentication that they are subject to eavesdropping attack, thus they should be used in secure communication environment such as HTTPS. In OAuth 2.0 MAC token which was devised as an authentication scheme that can be used in non-secure communication environment, server issues shared secret key to authenticated client and the client uses it to compute MAC to prove the authenticity of request, but in this case server has to store and use the shared secret key to verify user's request. Therefore, it's hard to provide stateless authentication service. In this paper we present a randomized token authentication scheme which can provide stateless MAC token authentication without storing shared secret key in server side. To remove the use of HTTPS, we utilize secure communication using server certificate and simple signature-based login using client certificate together with the proposed randomized token authentication to achieve the fully stateless authentication service and we provide an implementation example.

• Journal of the Korea Convergence Society
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• v.10 no.10
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• pp.21-26
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• 2019

At present, it is indispensable to utilize data as an information society. Therefore, the database is used to manage large amounts of data. In real life, most of the data in a database is the personal information of a group of members. Because personal information is sensitive data, the role of the database administrator who manages personal information is important. However, there is a growing number of attacks on databases to use this personal information in a malicious way. SQL Injection is one of the most known and old hacking techniques. SQL Injection attacks are known as an easy technique, but countermeasures are easy, but a lot of efforts are made to avoid SQL attacks on web pages that require a lot of logins, but some sites are still vulnerable to SQL attacks. Therefore, this study suggests effective defense measures through analysis of SQL hacking technology cases and contributes to preventing web hacking and providing a secure information communication environment.

• The KIPS Transactions:PartC
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• v.11C no.4
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• pp.485-496
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• 2004

The wide spread of Internet makes susceptible to the attacks via communication Web from hackers using the vulnerability of both computer and network systems. In this paper, we design and implement an integrated security system, named as LISS(Linux-based Integrated Security System) in which an integrated security management is possible. This system is based on the open operating system, Linux and consists of open security tools, which is effective in security management of Linux based-servers. We also construct a test-bed in order to testify the performance of the LISS. It is revealed that the implemented system captures all the attack Patterns generated from Network Mapper.