• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.229-230
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• 2008

Recently, our lives have become more convenient and our work more efficient as a result of these cell phones. On the other hand, they have also caused diverse side-effects, including threats of blackmail with invasion of privacy, disclosure of personal information, as well as security breaches, and an overall increase in distrust between people. Recognizing the need to quickly collect digital evidence with an increase in cell phone crimes, this paper proposes to develop such standard module.

• Journal of Digital Convergence
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• v.10 no.3
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• pp.99-104
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• 2012

The digital forensics are new kinds of security that investigate and verificate fact relation about activities based on digital data. In this paper, we implemented digital forensic tool that can be used in collecting, analyzing, and reporting evidences. This tool support intuitional GUI that everybody can analyze easily. And a simple operation can collect and analyze active data. Also, we can decrease much time and endeavor by using this forensic tool that support reliable data.

• Journal of Internet Computing and Services
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• v.13 no.3
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• pp.49-59
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• 2012

Throughout developing digital technology, reproduction of image is growing better day by day. And at the same time, diverse image editing softwares are developed to manage images easily. In the process of editing images, those programs could delete or modify EXIF files which have the original image information; therefore images without the origin source are widely spread on the web site after editing. This matter could affect analysis of images due to the distortion of originality. Especially in the court of law, the source of evidence should be expressed clearly; therefore digital image EXIF file without deletion or distortion could not be the objective evidence. In this research, we try to trace the identification of a digital camera in order to solve digital images originality, and also we focus on lens distortion correction algorism which is used in digital image processing. Lens distortion correction uses mapping algorism, and at this moment it also uses interpolation algorism to prevent aliasing artifact and reconstruction artifact. At this point interpolation shows the similar mapping pattern; therefore we want to find out the interpolation evidence. We propose a minimum filter algorism in order to detect interpolation pattern and adjust the same minimum filter coefficient in two areas; one has interpolation and the second has no interpolation. Throughout DFT, we confirm frequency character between each area. Based on this result, we make the final detection map by using differences between two areas. In other words, thereby the area which has the interpolation caused by mapping is adjusted using minimum filter for detection algorism; the second area which has no interpolation tends to different frequency character.

• Journal of Advanced Navigation Technology
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• v.17 no.1
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• pp.63-68
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• 2013

Recently, companies seek a way to overcome their financial crisis by reducing costs in the field of IT. In such a circumstance, cloud computing is rapidly emerging as an optimal solution to the crisis. Even in a digital forensic investigation, whether users of an investigated system have used a cloud service is a very important factor in selecting additional investigated subjects. When a user has used cloud services, such as Daum Cloud and Google Docs, it is possible to connect to the could service from a remote place by acquiring the user's log-in information. In such a case, evidence data should be collected from the remote place for an efficient digital forensic investigation, and it is needed to conduct research on the collection and analysis of data from various kinds of cloud services. Thus, this study suggested a digital forensic framework considering cloud environments by investigating collection and analysis techniques for each cloud service.

• Journal of KIISE
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• v.45 no.3
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• pp.311-320
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• 2018

Recently, the use of digital audio and video as proof in criminal and all kinds of litigation is increasing, and scientific investigation using digital forensic technique is developing. With the development of computing and file editing technologies, anyone can simply manipulate video files, and the number of cases of manipulating digital data is increasing. As a result, the integrity of the evidence and the reliability of the evidence Is required. In this paper, we propose a technique for extracting the Electrical Network Frequency (ENF) through a grid of power grids according to the geographical environment for power supply, and then performing signal processing for peak detection using QIFFT. Through the detection algorithm using the standard deviation, it was confirmed that the video file was falsified with 73% accuracy and the forgery point was found.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2595-2601
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• 2013

Currently, under being related with confiscation method of digital store medium from the court of justice, "the sorting confiscation method of principle, the exceptional medium confiscation method" from in section3 no.106 of the criminal procedure code disregard the actual fields of investigation. What is more, there are many difficulties to execute cases by observing this for the achievement of confiscation purpose. At this point, I present the problems of the present confiscation search method and the desirable scene confiscation search method and the improvement program under the new technology circumstance.

• Journal of Korea Multimedia Society
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• v.24 no.9
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• pp.1299-1310
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• 2021

Under the background of the rapid development of digital educational games, we have to evidently research the elements of the achievement system of children's DEG (Digital Educational Game), and analyze the relations between the elements and make a profound study on the achievement system and its components on the impact of player's attitude. Compared with the existing research, the research contents and methods are innovative and reliable. The results show that players have a positive attitude towards the DEG achievement system, DEG achievement system has important value and role for educational games. Which is made of five elements: symbol, reward, logic, social interaction, and knowledge. The five elements interact with each other and have a positive impact on players' attitudes. DEG achievement system with five elements will bring players a positive experience. These findings provide a detailed study of the components of the achievement system. With all of these, we can explain the role and relationship of the components, and provide new ideas and empirical evidence for the design and development of children's educational game achievement system. The above findings provide a detailed description of the components of the DEG achievement system, explain the role and value of each component, and the relationships and patterns among the components, it provides a new perspective and empirical evidence for the design and development of the children's system DEG results.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.1
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• pp.87-96
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• 2006

In this paper, we examine general digital evidence collection process which is according to RFC3227 document[l], and establish specific steps for memory information collection. Besides, we include memory dump process to existing digital evidence collection process, and examine privacy information through dumping real user's memory and collecting pagefile which is part of virtual memory system. Especially, we discovered sensitive data which is like password and userID that exist in the half of pagefiles. Moreover, we suggest each analysis technique and computer forensic process for memory information and virtual memory.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.135-152
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• 2016

Because of the evolution of mobile devices such as smartphone, the necessity of mobile forensics is increasing. In spite of this necessity, the mobile forensics does not fully reflect the characteristic of the mobile device. For this reason, this paper analyzes the legal, institutional, and technical considerations for figuring out facing problems of mobile forensics. Trough this analysis, this study discuss the limits of screening seizure on the mobile device. Also, analyzes and verify the mobile forensic data acquisition methods and tools for ensuring the admissibility of mobile forensic evidence in digital investigation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9C
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• pp.1345-1351
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• 2004

Due to the overwhelming importance the Internet gained nowadays, more and more sophisticated security services are requested. However many applications such as Internet Banking, Home Trading System, Electronic Medical Recede, electronic commerce, etc. are related to non-repudiation. Non-repudiation services are one of these new security requirements. ill comparison to other security issues, such as privacy or authenticity of communications, non-repudiation has not been studied intensively. Informally, we say that a protocol is fair if at the end of the protocol execution either originator receives a non-repudiation of receipt evidence and recipient receives a non-repudiation of origin evidence or none of them receives any valid evidence. The most non-repudiation protocols rely on a trusted third party(TIP) that has to intervene during each protocols run. the TIP may create a communication bottleneck. ill this paper, we suggest the digital signature recorder that guarantees fairness logically and supplies minimal network bottleneck to be composed verification server physically.