• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.5
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• pp.27-38
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• 2007

One of the most important security issues of e-mail service is user privacy. Currently, various security protocols, like PGP(pretty Good Privacy), S/MIME(Secure/Multipurpose Internet Mail Extension), have been proposed. These protocols, however, do not provide forward secrecy. Recently, some security protocols that provide forward secrecy were proposed. But all of them require changes to the current e-mail infrastructure. Moreover, contrary to authors' intention, some of them do not actually provide perfect forward secrecy. In this paper, we propose a new practical e-mail security protocol. The proposed protocol provides perfect forward secrecy and uses a practical e-mail model that dose not require any changes to existing e-mail servers. It encrypts and authenticates messages efficiently using elliptic curve based signcryption scheme. In addition, we provide a way to send secure group e-mails.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.115-124
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• 2008

In vehicular networks, vehicles should be able to authenticate each other to securely communicate with network-based infrastructure, and their locations and identifiers should not be exposed from the communication messages. however, when an accident occurs, the investigating authorities have to trace down its origin. As vehicles communicate not only with RSUs(Road Side Units) but also with other vehicles, it is important to minimize the number of communication flows among the vehicles while the communication satisfies the several security properties such as anonymity, authenticity, and traceability. In our paper, when the mutual authentication protocol is working between vehicles and RSUs, the protocol offers the traceability with privacy protection using pseudonym and MAC (Message Authentication Code) chain. And also by using MAC-chain as one-time pseudonyms, our protocol does not need a separate way to manage pseudonyms.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.1
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• pp.147-155
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• 2003

The diffusion of internet infrastructure and a fast increase of Population to use it is becoming a base of the service that can use various information, data and digital contents which were provided through off-line physically and used. Recently, the. techniques for copy deterrence and copyright protection have been important in e-commerce because various contents in digital form can be duplicated easily. The Access Control(AC) technique that only a user having the qualifications can access and use contents normally has been studied. The Conditional Access System(CAS) used in a satellite broadcasting md Digital Right Management System(DRMS) used for contents service are representative models of current commercialized access control. The CAS and DRM can be considered as an access control technique based on the payment based type(PBT). This paper describe the access control method of payment free type(PFT) suggested in ［5］ which are independent on the payment structure. And then we suggest a new access control method of payment free type which is more efficient than the previous one.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.5
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• pp.47-57
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• 2006

Mobile Ad-hoc networks have various implementation constraints such as infrastructure-free, no trusted authority, node mobility, and the limited power and small memory of mobile device. And just like wired networks, various security issues such as authentication, confidentiality, integrity, non-repudiation, access control, availability and so on have been arisen in mobile Ad-hoc networks. But we focus on authentication of these security issues because it is quitely affected by the characteristics of networks. In this paper, we propose the authentication protocol that can limit the size of certificate repository as $log_2N$ and assures to make a trusted certificate path from one node to another, adopting the concept of Hamming distance. Particularly, our protocol can construct a trusted certificate path in spite of decreasing or increasing the number of nodes in mobile Ad-hoc network.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.1
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• pp.81-91
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• 2012

Presently in 2011, there are countless attacking tools oriented to invading security on the internet. And most of the tools are possible to conduct the actual invasion. Also, as the program sources attacking the weaknesses of PS3 were released in 2010 and also various sources for attacking agents and attacking tools such as Stuxnet Source Code were released in 2011, the part for defense has the greatest burden; however, it can be also a chance for the defensive part to suggest and develop methods to defense identical or similar patterned attacking by analyzing attacking sources. As a way to cope with such attacking, this study divides the network areas targeted for attack based on load balancing by the approach gateways and communication lines according to the defensive policies by attacking types and also suggests methods to multiply communication lines. The result of this paper will be provided as practical data to realize defensive policies based on high hardware performances through enhancing the price competitiveness of hardware infrastructure with 2010 as a start.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.2
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• pp.267-281
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• 2012

SCADA system is a computer system that monitors and controls the national infrastructure or industrial process including transportation facilities, water treatment and distribution, electrical power transmission and distribution, and gas pipelines. The SCADA system has been operated in a closed network, but it changes to open network as information and communication technology is developed rapidly. As the way of connecting with outside user extends, the possibility of exploitation of vulnerability of SCADA system gets high. The methodology to protect the possible huge damage caused by malicious user should be developed. In this paper, we proposed anomaly detection based intrusion detection methodology by estimating self-similarity of SCADA system.

• International Journal of Computer Science & Network Security
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• v.21 no.3
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• pp.219-228
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• 2021

The adoption of new technology in any organization will represent change, and such change needs user acceptance for its successful implementation. Saudi Arabian health centers are no exception; therefore, the current study will investigate the adoption of new technology, namely that of virtual reality (VR), within health centers in Saudi Arabia and specifically in Riyadh City. This study explores the current state of VR technology adoption, factors that influence such adoption, and the extent of this technology's efficiency when it is used for vaccinating children. The data were collected from two samples: workers in vaccination clinics who responded to a survey and a group of children who participated in the VR technology experiment. The current study proposed a model based on the unified theory of acceptance and use of technology 2 (UTAUT2), with the addition of two variables: personal innovativeness and satisfaction. The results indicated that the respondents' perceptions regarding the health centers' infrastructure in terms of adopting VR were moderate. Among the factors affecting VR adoption, satisfaction, personal innovativeness, and behavioral intention were identified as vastly influential factors. From the eight hypotheses, six were found to be supported, with their factors significantly influencing behavioral intention with regard to VR technology adoption. Besides, the experiment concerning the use of VR technology on children verified the technique's high efficiency in terms of providing pain management and fear removal. These findings support the continuity of VR technology use, expand its future application fields, and integrate this study into the literature on technology acceptance models for VR adoption, as limited studies have covered this topic; consequently, this will benefit future research in this field.

• Journal of the Korean Society of Safety
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• v.36 no.1
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• pp.18-25
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• 2021

In many developed countries, such as South Korea, efficiently maintaining the aging infrastructures is an important issue. Currently, inspectors visually inspect the infrastructure for maintenance needs, but this method is inefficient due to its high costs, long logistic times, and hazards to the inspectors. Thus, in this paper, a novel crack inspection approach for concrete bridges is proposed using integrated image processing techniques. The proposed approach consists of four steps: (1) training a deep learning model to automatically detect cracks on concrete bridges, (2) acquiring in-situ images using a drone, (3) generating orthomosaic images based on 3D modeling, and (4) detecting cracks on the orthmosaic image using the trained deep learning model. Cascade Mask R-CNN, a state-of-the-art instance segmentation deep learning model, was trained with 3235 crack images that included 2415 hard negative images. We selected the Tancheon overpass, located in Seoul, South Korea, as a testbed for the proposed approach, and we captured images of pier 34-37 and slab 34-36 using a commercial drone. Agisoft Metashape was utilized as a 3D model generation program to generate an orthomosaic of the captured images. We applied the proposed approach to four orthomosaic images that displayed the front, back, left, and right sides of pier 37. Using pixel-level precision referencing visual inspection of the captured images, we evaluated the trained Cascade Mask R-CNN's crack detection performance. At the coping of the front side of pier 37, the model obtained its best precision: 94.34%. It achieved an average precision of 72.93% for the orthomosaics of the four sides of the pier. The test results show that this proposed approach for crack detection can be a suitable alternative to the conventional visual inspection method.

• Journal of Korea Planning Association
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• v.54 no.4
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• pp.109-121
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• 2019

The purpose of this study is to understand the perceptions of stakeholders in environmental conflicts. The private rental housing project in Busan Sasang-gu Jurye 3 District, which took place in 2017 is one of many cases of environmental conflicts between developers and local residents. The case is considered as a typical failure of collaborative governance that has consequently caused negative impacts to both local residents and government. To understand why local residents could not come to consensus even though the majority of them were against the development project, we analyzed residents' perceptions and subjective opinions towards environmental conflicts. This study adopted 'Q methodology' to investigate human subjectivity. The results showed three distinguished types of subjectivity structures. Each type was named as 'collaborative governance advocates', 'public administration distrusters', and 'current local government supporters' based on their characteristics. Participants in all three types showed opposition to environmental damages that can be caused by the private rental housing development, but they revealed different perspectives on the importance of public participation and institutional responsibility in the process of decision-making. This study makes better understand what makes it difficult to build collaborative governance as a means of overcoming environmental conflicts.

• The Journal of Information Systems
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• v.30 no.2
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• pp.147-163
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• 2021

Purpose The study aims to predict real estate prices by utilizing regional characteristics. Since real estate has the characteristic of immobility, the characteristics of a region have a great influence on the price of real estate. In addition, real estate prices are closely related to economic development and are a major concern for policy makers and investors. Accurate house price forecasting is necessary to prepare for the impact of house price fluctuations. To improve the performance of our predictive models, we applied LSTM, a widely used deep learning technique for predicting time series data. Design/methodology/approach This study used time series data on real estate prices provided by the Ministry of Land, Infrastructure and Transport. For time series data preprocessing, HP filters were applied to decompose trends and SOM was used to cluster regions with similar price directions. To build a real estate price prediction model, SVR and LSTM were applied, and the prices of regions classified into similar clusters by SOM were used as input variables. Findings The clustering results showed that the region of the same cluster was geographically close, and it was possible to confirm the characteristics of being classified as the same cluster even if there was a price level and a similar industry group. As a result of predicting real estate prices in 1, 2, and 3 months, LSTM showed better predictive performance than SVR, and LSTM showed better predictive performance in long-term forecasting 3 months later than in 1-month short-term forecasting.