• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.9
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• pp.555-560
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• 2014

Recently, there are many researches on sharing group session key for members in a group. Among them, Harn and Lin proposed a scheme based on the Shamir's group session key and Liu, Cheng, Cao, and Jiang improved it to reduce the specific weakness. Especially, these schemes are based on the finite integer ring to protest the insider attack, in which a valid member can derived another member's secret using known information. In this paper, it is shown that the finite integer ring implies the failure of the reconstruction of group session key depending on the adopted parameters. We fix this problem and propose new group session key transfer scheme using the Shamir's secret sharing.

• The KIPS Transactions:PartA
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• v.12A no.5 s.95
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• pp.433-440
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• 2005

The sharing of objects for authoring frequently occurs among participating users in a cooperative authoring system where many users can collaborate. Floor control is therefore needed not only for minimizing the race condition during object accesses but also for ensuring the exclusive use of objects. h floor is a temporary access right that is given to a participating user who wants to use a shared object. Although the floor control methods for a single session environment can be found in various literature, those methods for a multi-session environment can hardly be found. In a multi-session environment, an object can be shared by multiple sessions. As a solution to the problems due to object sharing in such an environment, this paper presents a floor control method based on the chair-of-chair guidance. This method is an extension of those based on traditional chair guidance; the chair-of-chair elected among session chairs exists in this method.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.81-81
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• 2017

• Journal of Internet Computing and Services
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• v.13 no.2
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• pp.21-32
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• 2012

We develop architecture of a virtual aggregation gateway (VAG) which enables composite application streaming based on N-Screen-as-a-Service (NaaS) using cloud computing in thin-client environment. We also discuss the problem of server computing burden in large scale multi-client case for screens sharing with composite application streaming over the internet. In particular, we propose an efficient Framework of N-Screen Session Manager which manages all media signaling that are necessary to deliver demanded contents. Furthermore, it will provides user with playback multimedia contents method (TV Drama, Ads, and Dialog etc) which is not considered in other research papers. The objectives of proposing N-Screen Session Manager are to (1) manage session status of all communication sessions (2) manage handling of received request and replies (3) allow users to playback multimedia contents anytime with variety of devices for screen sharing and (4) allow users to transfer an ongoing communication session from one device to another. Furthermore, we discuss the major security issues that occur in Session Initiation Protocol as well as minimizing delay resulted from session initiations (playback or transfer session).

• The KIPS Transactions:PartC
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• v.10C no.2
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• pp.155-162
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• 2003

Fast restoration time and service guarantee are the important goals to achieve the network reliability. In the protection switching scheme, one way to guarantee service fro an application session if a network happens to fail is to establish the restoration path that amounts to the same bandwidth of the working path of the session at the same time. When we setup the restoration path, we can reduce the bandwidth consumption by the restoration path if the path can share the bandwidth required by the other paths. This paper explains the methods how to determine the shared bandwidth of the restoration path in the protection switching scheme, given the maximum bandwidth assigned to a link along the working path. We point out that such sharing algorithm can not reduce the bandwidth consumption by the restoration paths in some cases, which contradict the general conception. We explain why this can happen, and show the simulation results in real network topologies to prove our arguments. We explain the reason of the failure of the sharing effect by the simple sharing algorithm. Finally we propose the way of how we can overcome the failure of the sharing effect, using the complete sharing algorithm based on the link database and showing the results.

• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.21-33
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• 2022

This paper is to suggest the secure secret sharing system in order to outstandingly reduce the damage caused by the leakage of the corporate secret. This research system is suggested as efficient P2P distributed system kept from the centrally controlled server scheme. Even the bitcoin circulation system is also based on P2P distribution scheme recenly. This research has designed the secure circulation of the secret shares produced by Threshold Shamir Secret Sharing scheme instead of the shares specified in the torrent file using the simple, highly scalable and fast transferring torrent P2P distribution structure and its protocol. In addition, this research has studied to apply both Shamir Threshold Secret Sharing scheme and the securely strong multiple user authentication based on Collaborative Threshold Autentication scheme. The secure transmission of secret data is protected as using the efficient symmetric encryption with the session secret key which is safely exchanged by the public key encryption. Also it is safer against the leakage because the secret key is effectively alive only for short lifetime like a session. Especially the characteristics of this proposed system is effectively to apply the threshold secret sharing scheme into efficient torrent P2P distributed system without modifying its architecture of the torrent system. In addition, this system guaranttes the confidentiality in distributing the secret file using the efficient symmetric encryption scheme, which the session key is securely exchanged using the public key encryption scheme. In this system, the devices to be taken out can be dynamically registered as an user. This scalability allows to apply the confidentiality and the authentication even to dynamically registerred users.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.557-561
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• 2020

This paper explores the attitudes of accounting students toward knowledge sharing at Umm Al-Gura University for the academic year 2013-2014. The study explored knowledge sharing among 202 accounting students at Umm Al-Gura University in session during the 2013-2014 academic year. Primary data came from a 3-item questionnaire collected from students; secondary data were source from scholarly publication. Descriptive statistics was used. The findings of this study revealed that the students had a medium to high degree of positive attitude toward knowledge sharing. The students had a positive perception of the use of knowledge sharing in supporting their education. The findings are essential for several stakeholders, such as university policymakers, lecturers, and the students, to provide a deeper understanding of knowledge sharing at the university education level. The findings may encourage policymakers at the university and the classroom levels to organize activities that promote knowledge sharing such as seminars, symposiums, or knowledge sharing exercises during the classroom hours to raise the students' knowledge sharing behavior and enhance education. The results of this study should be useful to policy makers at the university level and the classroom level as there is a positive attitude in disseminating knowledge in the higher educational setting.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2008.10b
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• pp.445-448
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• 2008

The key establishment between nodes is one of the most important issues to secure the communication in wireless sensor networks. Some researcher used the probabilistic key sharing scheme with a pre-shared key pool to reduce the number of keys and the key disclosure possibility. However, there is a potential possibility that some nodes do not have a common share in the key pool. The purpose of this paper is to devise a peer to peer key sharing protocol (PPKP) based on Quorum system and Diffie-Hellman key exchange scheme (DHS). The PPKP establishes a session key by creating a shared key using the DHS and then scrambles it based on Quorum system to secure that. The protocol reduces the number of necessary keys than the previous schemes and could solve the non-common key sharing possibility problem in the probabilistic schemes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06b
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• pp.99-104
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• 1998

Application sharing is the ability to use existing applications, such as Excel or MS-Word, during a group session without modification. In this paper, we present the design and implementation of an application sharing system, called ShareIt, which enable users to share arbitrary MS-Windows applications under the Win 3.1/95/NT and X window system, and evaluation of the system performance. To share an application, the image of the application window is captured and transmitted to other sites. With the use of the window capturing method, ShareIt allows any MS-Windows application to be shared regardless of not only the window systems but also the version-up of window systems.

• Journal of KIISE:Information Networking
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• v.31 no.4
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• pp.353-362
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• 2004

Mobile Ad-Hoc network tends to expose scarce computing resources and various security threats because all traffics are carried in air along with no central management authority. To provide secure communication and save communication overhead, a scheme is inevitable to serurely establish session keys. However, most of key establishment methods for Ad-Hoc network focus on the distribution of a group key to all hosts and/or the efficient public key management. In this paper, a secure and efficient scheme is proposed to establish a session key between two Ad-Hoc nodes. The proposed scheme makes use of the secret sharing mechanism and the Diffie-Hellman key exchange method. For secure intra-cluster communication, each member node establishes session keys with its clusterhead, after mutual authentication using the secret shares. For inter-cluster communication, each node establishes session keys with its correspondent node using the public key and Diffie-Hellman key exchange method. The simulation results prove that the proposed scheme is more secure and efficient than that of the Clusterhead Authentication Based Method(1).