• 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.

• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1277-1285
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• 2003

In this paper, we present a conference key authentication mechanism by employing an algebraic method on IMT-2000 environment. To accomplish this, the symmetric balanced incomplete block design is applied for generating a conference key and then this key is distributed to participants. Through the technique for creation of a conference key and mutual authentications peformed based on identification information, a communication protocol is designed. The protocol proposed minimizes the communication complexity for generating a conference key. On a special case the complexity is O(equation omitted), where v is the number of participants. The security of the mechanism, which is a significant problem in construction of secure systems, can be assured since finding discrete logarithms is generally a hard problem.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.592-593
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• 2005

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.778-779
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• 2005

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09a
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• pp.780-781
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• 2005

• Proceedings of the Korea Water Resources Association Conference
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• 2005.09b
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• pp.1271-1273
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• 2005

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.286-286
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• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.496-500
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• 2001

When we cut a key way on the axial or on the boss, we generally use a slotter or a broach. To do the key seating, turing operations have to be preceded and then the key on the axial or on the boss can be seated. For this reason, the production process of key way cutting becomes complicated. If is necessary to simplify the process and we have developed a small practical machine for key way cutting. The machine is located on the carriage of the lathe. Using this small and practical key way machine, after operation the turing, you do not have to remove the workpiece from the chuck of the lathe to carry on the key seating process. The developed machine will save cutting time and the cost.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.213-216
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• 2001

Key frame extraction is an important method of summarizing a long video. This paper propose a technique to automatically extract several key frames representative of its content from video. We use the color layout descriptor to select key frames from video. For selection of key frames, we calculate similarity of color layout features extracted from video, and extract key frames using similarity. An important aspect of our algorithm is that does not assume a fixed number of key frames per video; instead, it selects the number of appropriate key frames of summarizing a long video Experimental results show that our method using color layout descriptor can successfully select several key frames from a video, and we confirmed that the processing speed for extracting key frames from video is considerably fast.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.4
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• pp.265-269
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• 2009

A conference key agreement system is a scheme to generate a session key in a contributory manner in order to communicate with each other securely among participants. In this paper an efficient conference key agreement system is proposed by employing symmetric balanced incomplete block design(SBIBD), one class of block designs. The protocol presented not only minimizes the message overhead and message exchanging rounds but also makes every participant contribute evenly for generating a conference key. Our protocol constructs a conference key which takes modified Diffe-Helman form of ${\prod}_{i=0}^{v-1}R_i$, where v is the number of participants and $R_i$ is a random number generated from member i. In a special class of SBIBD, it takes only 3 rounds message exchange and message overhead is $O(v{\sqrt{v}})$. Our protocol can be proved as computationally difficult to calculate as discrete logarithms.