• The Journal of the Korea Contents Association
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• v.9 no.4
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• pp.95-102
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• 2009

Recently, remote user authentication scheme protecting user anonymity using smart card has been researched with interest increasing on user privacy. Although authentication scheme providing user anonymity using smart card had been proposed by Das et al, Chien et al. pointed out Das et al. scheme fail to provide user anonymity and proposed new scheme to overcome the problem. A remote system Kim et al. proposed a scheme which is traceable about malicious user with protecting user anonymity. In this paper, we point out that Kim et a1. scheme fail to provide user anonymity and propose a scheme for some problems Kim et al. scheme has. And then we analysis our scheme on cryptophic security and efficiency with Kim scheme.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.66-73
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• 2008

The concept of u-Vehicle is a technological model that people try to build the ubiquitous world in the car which moves, by using the RFID technology as well as the telematics service based on the location. RFID is weak on the point of information security because RFID has possibility for being abused such as chasing, counterfeiting, and invading personal privacy. RFID's tags use a weak cryptographic algorithm. This paper presents the vulnerabilities of information security under u-Vehicle environments. To solve that, we propose a mechanism enhancing RFID tag's security but with low cost by reducing the number of mutual authentication stages and using the hash function.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.5
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• pp.899-905
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• 2009

IPTV service is one of the representatives for the integration of broadcasting industry and communication industry, which also can meet users' various demands and provide efficient service. As the increasing number of IPTV users and contents servers, it is necessary to provide the safety authority system to prevent the illegal audio-visual, incorrect audio-visual authority, and illegal authority control. This thesis puts forward PKI(public Key Infrastructure) as the foundation key production mechanism. Through this mechanism, the key can be transferred safely to users and authenticate the ID of users and contents servers. In a word, our system can provide safe and efficient service for mutual authentication.

• The Journal of the Korea Contents Association
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• v.6 no.1
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• pp.170-178
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• 2006

In this paper, the hybrid-watermarking method to make it possible to the authentication, modification detection and copyright protection of the digital image was proposed. After the original image is transformed by the DWT(Discrete Wavelet Transform), the encrypted watermark information is embedded into the LSB(Least Significant Bit) of LL band on the low frequence domain for authenticating and detecting modified position in the image. And watermark information is embedded by exchanging the wavelet coefficient for the copyright protection. Thereby, we can authenticate the modification and detect the modified location by extracting the values of LSB on the low frequence domain. And we can perceive the copyright information of original image by extracting the embedded watermark on the high frequence domain.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.105-113
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• 2009

The previous key management methods are not appropriate for secure data communication in cluster-based routing scheme. Because cluster heads are elected in every round and communicate with the member nodes for authentication and share-key establishment phase in the cluster. In addition, there are not considered to mobility of nodes in previous key management mechanisms. In this paper, we propose the secure and effective key management mechanisim in the cluster-based routing scheme that if there are no share keys between cluster head and its nodes, we create the cluster key using authentication with base station or trust autentication and exchange the their information for a round.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.99-106
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• 2014

In this paper, we analyze weaknesses of the biometrics-based user authentication scheme proposed by An. The result of analysis An's authentication scheme by the login success scenario proposed in this paper, if the attacker successes to get user's random number, he/she can pass user authentication phase of the legal server. Also the biometrics guessing scenario proposed in this paper shows the legal user's the biometric information is revealed in lost smart card. Since An's authentication scheme submit user ID and biometrics in plain text to the server, it is very vulnerable to inner attack and it is not provide the user anonymity to the server as well as the one to the third by user ID in plain text. Besides An's authentication scheme is contextual error too, due to this, it has weakness and so on that it did not check the validity of the smart card holder.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.759-766
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• 2017

In this paper, we preserve the transparency of digital contents by compressing and storing the medical image for a certain period so as to be safe and robust against various attacks of medical images. The proposed algorithm generates an encrypted image authentication code that extracts the feature value of the original image and combines it with the user's information. in order to extract hidden data, the authentication code is first decrypts the encrypted medical image and extracts the hidden data using the spatial characteristics of image. The proposed algorithm guarantees integrity when comparing extracted authentication code and newly generated authentication code for image authentication after directly inserting it into content itself through watermarking. We have proved various security of attack of image data and proved that the certification rate is improved to 98.4%.

• Journal of the Korea Convergence Society
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• v.6 no.6
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• pp.185-193
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• 2015

The wisdom contents consists of an ordinary person's ideas and experience. The Wisdom Market [1] is an online business model where wisdom contents are traded. Thus, the general public could do business activities in the Wisdom Market at ease. As the wisdom contents are themselves the thought of persons, there exists many similar or duplicated contents. Existing copyright protection schemes mainly focus on the primary author's right. Thus, it's not appropriate for protecting the contents of Collective Intelligence that requires to protect the rights of collaborators. There should exist a new method to be dynamic capable of combining and deleting rights of select collaborators. In this study, we propose collective copyright authentication scheme suitable for the contents of Collective Intelligence. The proposed scheme consists of collective copyright registration, addition and verification protocols. It could be applied to various business models that require to combine multiple rights of similar contents or to represent multiple authorships on the same contents.

• The Journal of the Korea Contents Association
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• v.4 no.3
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• pp.53-60
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• 2004

In this paper we present user authentication and key distribution using threshold PKC(Public Key Cryptosystem), which is secure against the dictionary attack. The n servers hold a t-out-of-n sharing of the dealer's secret key. When the server authenticate a user, at least f of them cooperate they can reconstruct password verifier.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.407-408
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• 2006

In this paper, we propose a new reversible image authentication technique based on watermarking where if the image is authentic, the distortion due to embedding can be completely removed from the watermarked image after the hidden data has been extracted. This technique utilizes histogram characteristics of the difference image and modifies pixel values slightly to embed more data than other reversible data hiding algorithm. The proposed scheme is quite simple and the execution time is rather short. Experimental results demonstrate that the proposed scheme can detect any modifications of the watermarked image.