• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.239-240
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• 2016

모바일 환경이 발전하면서 다양한 스마트폰 중 안드로이드 기반의 스마트폰이 시장 점유율을 높여가고 있다. 하지만 최근 보안 이슈로 인해 애플사에서 만든 아이폰을 사용하는 사람이 증가하고 있다. 따라서 아이폰에 대한 어플리케이션 시장 역시 증가 추세이다. 하지만 안드로이드 기반 스마트폰은 어느 정도 소스코드가 공개되어있기에 개발 및 분석이 수월하지만, 애플사의 아이폰은 공개된 소스코드가 극히 적어 개발 및 분석이 상대적으로 어렵다. 따라서 아이폰 애플리케이션에서 오류 발생 시 시스템 라이브러리에서 발생하는 오류는 효율적으로 대처하기가 힘들다. 본 논문은 더 효율적으로 애플리케이션들을 개발하고 유지 및 보수 할 수 있도록 Mac OS X에서 LLDB를 이용한 아이폰 애플리케이션 역공학 분석 방법론을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8B
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• pp.502-508
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• 2007

This paper proposes a method to shut out all of the not certified network access packet by embodying the two-factor(MAC ADDRESS, ID/PASSWORD) authentication system. The Authenticating Gateway System takes over central server's policy and permit or hold up the packet by inherited policy. And checks the whether or not patched the OS version and getting influenced from computer virus. And takes the information about client's resources(H/W, S/W) without Agent in the client. That makes more stability of network operating circumstance and fast facing the attack from hackers. In the fixed mobile network circumstance, This method provides more simplicity and less expenses than IEEE802.1x authentication system(cisco nac).

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.30-35
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• 2008

The purpose of this study is to analyze and define user's emotional satisfaction factors to the PC OS GUI image. The study is to investigate the relationship between PC OS GUI Image and Sensitive Vocabula교 based on user's emotional preference. 47 user preferred sensitive words are collected by the initial survey. Through the similarity test, 47 words are narrowed down to 20 comprehend words. The semantic differential methods is used in the final survey with 5 step questionnaire. From this process, user preferred the GUI design that is vocabularized as Clear, Easy, Safety, Stability. Additionally, the result shows that the image of Clear is related to Safety and the image of Easy is related to Stability. The result of the study could be used in design PC OS GUI as base data.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.4
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• pp.35-42
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• 2010

This paper reviews the current studies about the current secure OS, security module and SELinux, and suggests Linux access control module that uses the user discriminating authentication, security authority inheritance of subjects and objects, reference monitor and MAC class process and real-time audit trailing using DB. First, during the user authentication process, it distinguishes the access permission IP and separates the superuser(root)'s authority from that of the security manager by making the users input the security level and the protection category. Second, when the subjects have access to the objects through security authority inheritance of subjects and objects, the suggested system carries out the access control by comparing the security information of the subjects with that of the objects. Third, this system implements a Reference Monitor audit on every current events happening in the kernel. As it decides the access permission after checking the current MAC security attributes, it can block any malicious intrusion in advance. Fourth, through the real-time audit trailing system, it detects all activities in the operating system, records them in the database and offers the security manager with the related security audit data in real-time.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.340-347
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• 2001

Security operating system applied to MAC(Mandatory Access Control) or to MLS(Multi Level Security) gives both subject and object both Security Level and value of Category, and it restrict access to object from subject. But it violates Security policy of system and could be a circulated course of illegal information. This is correctly IPC(Interprocess Communication)mechanism and Covert Channel. In this thesis, I tried to design and implementation as OS kernel in order not only to give confidence of information circulation in the Security system, but also to defend from Covert Channel by Storage and IPC mechanism used as a circulated course of illegal information. For removing a illegal information flow by IPC mechanism. I applied IPC mechanism to MLS Security policy, and I made Storage Covert Channel analyze system call Spec. and than distinguish Storage Covert Channel. By appling auditing and delaying, I dealt with making low bandwidth.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1871-1890
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• 2021

The transition toward a contactless society has been rapidly progressing owing to the recent COVID-19 pandemic. As a result, the IT environment of organizations and enterprises is changing rapidly; in particular, data security is expanding to the private sector. To adapt to these changes, organizations and companies have started to securely transfer confidential data to residential PCs and personally owned devices of employees working from home or from other locations. Therefore, organizations and companies are introducing streaming data services, such as the virtual desktop infrastructure (VDI) or cloud services, to securely connect internal and external networks. These methods have the advantage of providing data without the need to download to a third terminal; however, while the data are being streamed, attacks such as screen shooting or capturing are performed. Therefore, there is an increasing interest in prevention techniques against screen capture threats that may occur in a contactless environment. In this study, we analyze possible screen capture methods in a PC and a mobile phone environment and present techniques that can protect the screens against specific attack methods. The detection and defense for screen capture of PC applications on Windows OS and Mac OS could be solved with a single agent using our proposed techniques. Screen capture of mobile devices can be prevented by applying our proposed techniques on Android and iOS.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.40-42
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• 2011

Smart hand-held devices like iPhone, iPad, Andriod and other mobile-OS machines are becoming a well known part of our daily lives. Utilization of these devices has gone beyond the expectations of their inventors. Evolution of Apple's iOS from a mobile phone Operating System to a wholesome platform for Portable Gaming is an adequate proof. Using these smart devices people are downloading applications from numerous online App Stores. Utilizing remote storage facilities and confining themselves to computing power far below than an entry level laptop, netbooks have emerged. Google's idea of Chrome OS coupled with Google's AppEngine is an eye-opener for researchers and developers. Keeping all these industry-proven innovations in mind we are proposing a Context-Driven Cloud-Oriented Application Architecture for smart devices. This architecture enables our smart devices to behave smarter by utilizing very less of local resources.

• Journal of Digital Contents Society
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• v.18 no.7
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• pp.1393-1401
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• 2017

The Linux operating system is expanding to include desktops and servers, as well as mobile devices, automobiles and embedded devices, and is the dominant operating system category because it is freely available and open source software. However, the desktop market is dominated by Microsoft's Windows, and Apple's Mac OS is increasingly dominated by enthusiasts, but Linux's growth is stagnant. An important element to make up for this deficiency is the X Window System. Most Linux distributions still use the traditional X.org server as the X Window System, but it is heavy and slow. To replace it, a new X window system called Wayland emerged. Wayland is small and light enough to fit on an embedded or mobile device, so it can be mounted on the IoT related device as well as on the desktop. With the advent of Wayland, the change in the X window will accelerate the popularization of Linux.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4B
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• pp.184-191
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• 2008

NanoQplus, which is an embedded operating system for wireless sensor networks (WSNs) and developed by Electronics and Telecommunications Research Institute (ETRI), provides programmer-friendly preemptive multi-threading programming technique, but it has poor network protocol stack, as compared to TinyOS, one of the famous operating systems for WSNs. In this paper, we apply dynamic MANET on-demand routing (DYMO) protocol, which is being standardized in Internet Engineering Task Force (IETF), to NanoQplus. Since DYMO has been proposed for mobile ad-hoc networks (MANETs) and MANETs have less resource restrictions than WSNs, the basic DYMO protocol cannot be applied to WSNs without modifications. Moreover, coherence with MAC protocol should be considered in order to eliminate redundant data between MAC and network layers. Thus, we propose a modified version of the basic DYMO protocol for NanoQplus. The experimental results from a real sensor network test-bed show that the DYMO implementation using NanoQplus works efficiently in WSNs.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.3
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• pp.178-192
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• 2021

File system forensics typically focus on the contents or timestamps of a file, and it is common to work around file/directory centers. But to recover a deleted file on the disk or use a carving technique to find and connect partial missing content, the evidence must be analyzed using cluster-centered analysis. Forensics tools such as EnCase, TSK, and X-ways, provide a basic ability to get information about disk clusters, but these are not the core functions of the tools. Alternatively, Sysinternals' DiskView tool provides a more intuitive visualization function, which makes it easier to obtain information around disk clusters. In addition, most current tools are for Windows. There are very few forensic analysis tools for MacOS, and furthermore, cluster analysis tools are very rare. In this paper, we developed a tool named FACT (Forensic Analyzer based Cluster Information Tool) for analyzing the state of clusters in a HFS+ file system, for digital forensics. The FACT consists of three features, a Cluster based analysis, B-tree based analysis, and Directory based analysis. The Cluster based analysis is the main feature, and was basically developed for cluster analysis. The FACT tool's cluster visualization feature plays a central role. The FACT tool was programmed in two programming languages, C/C++ and Python. The core part for analyzing the HFS+ filesystem was programmed in C/C++ and the visualization part is implemented using the Python Tkinter library. The features in this study will evolve into key forensics tools for use in MacOS, and by providing additional GUI capabilities can be very important for cluster-centric forensics analysis.