• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1516-1523
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• 2004

In the paper, an algorithm fitted to P2P system was proposed by improving Kerberos which is an algorithm for mutual authentication. To keep the role of Kerberos and minimize load to server, the proposed algorithm imposed the server role of ticket recognition to the opposite peer. Using this method, the number of sewers as ticket recognition server was averted and function of server for authentication was minimized so that server load was mininized. The proposed algorithm enables the server to play the minimum of the role and to perform strong mutual authentication, while imposeing on the peers the role of authentication. To make suitable to P2P system, trial number oriented authentication limit was given, not time-oriented authentication expiration time. In the paper, a new P2P system was designed using this algorithm.

• Convergence Security Journal
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• v.15 no.7
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• pp.97-102
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• 2015

Recently, each country should operates a integrated disaster safety management system in order to reduce the damage, such as the world-natural disasters. In particular, research on digital signage use has been mad e by a method for transmitting a disaster warning message. In this paper, we tried to examine the security requirements that are required by the disaster safety netwo rk by looking at the digital signage concept and disaster safety management system. Also, in order to be tra nsmitted to the safe digital signage terminal a common alarm message in the disaster safety services using d igital signage, we propose a protocol that uses a public key authentication mechanism. The proposed protocol is to be safely displayed a common alarm message to the appropriate area.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1412-1415
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• 2002

This paper describes a digital signature-based method for original and updated video authentication. The method uses multiple digital signatures in dealing with video data undergoing multiple change/updating. In addition, a feature based on neighbouring block similarity measure is applied to deal with certain image/video modification. The proposed method can cope with wide range of image/video tampering. It is suitable for practical use of video data, where updating may be performed by more than one legal parties. Experimental results are included with concluding remarks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6C
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• pp.651-657
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• 2006

This paper propose the technique for the execution authentication of digital signature with TTS(traceable trust server) to guarantee the safe execution of mobile agents. That is to say, it is focused on improving the processing speed of systems and the traffic of network which are problems in the existing studies. The digital signature is used to guarantee the efficient and safe execution and the integrity of mobile agents. The certificate of it is chained with synthesis function, cryptographic algorithm based on public key, and hash function. And white hosts can be protected against the threat of being used maliciously. Then, we prove the efficiency of system overhead and the traffic of network by the analysis. In case the certificate chain of a digital signature is used, the safe execution of mobile agents can be protected against attackers that wish to insert a newly created certificate after cutting off the chain after striking space key 2 times.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.14 no.2
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• pp.3-13
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• 2004

DRM is the ability to brand digital contents with features that ensure copy Protection and affect the way in which digital contents are played back. DRM is a technology that enables the secure distribution, promotion and sale of digital contents on the Internet. The DRM Client System that operates on the untrusted user environments has to meet the requirements of the contents owner, including copyright and contents protection. After the DRM Client System is installed on the untrusted user environments, it verifies and plays digital contents. With these procedures it cuties out user authentication, contents decryption, and license management. During these procedures, the sensitive data, including authentication information, decryption data and license data, must be secured against any illegal access from users. The goal of this thesis is to introduce the implementation of Secure Storage Device which can protect user's authentication key, cryptographic key, and license data in safe where the DRM Client System is running.

• Journal of Korea Multimedia Society
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• v.24 no.8
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• pp.1044-1058
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• 2021

Tempered electronic contents have multiplied in last few years, thanks to the emergence of sophisticated artificial intelligence(AI) algorithms. Deepfakes (fake footage, photos, speech, and videos) can be a frightening and destructive phenomenon that has the capacity to distort the facts and hamper reputation by presenting a fake reality. Evidence of ownership or authentication of digital material is crucial for combating the fabricated content influx we are facing today. Current solutions lack the capacity to track digital media's history and provenance. Due to the rise of misrepresentation created by technologies like deepfake, detection algorithms are required to verify the integrity of digital content. Many real-world scenarios have been claimed to benefit from blockchain's authentication capabilities. Despite the scattered efforts surrounding such remedies, relatively little research has been undertaken to discover where blockchain technology can be used to tackle the deepfake problem. Latest blockchain based innovations such as Smart Contract, Hyperledger fabric can play a vital role against the manipulation of digital content. The goal of this paper is to summarize and discuss the ongoing researches related to blockchain's capabilities to protect digital content authentication. We have also suggested a blockchain (smart contract) dependent framework that can keep the data integrity of original content and thus prevent deepfake. This study also aims at discussing how blockchain technology can be used more effectively in deepfake prevention as well as highlight the current state of deepfake video detection research, including the generating process, various detection algorithms, and existing benchmarks.

• 전자공학회논문지 IE
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• v.43 no.2
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• pp.87-92
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• 2006

Many watermarking methods for protecting the intellectual property right and authentication multimedia data have been proposed in recent years. In image authentication watermarking, watermark is inserted into an image to detect any malicious alteration. So, watermark for authentication and integrity should be erased easily when the image is changed by scaling or cropping etc. We propose in this paper a fragile watermarking algorithm for image integrity verification and tamper localization proofing using special hierarchical structure. In the proposed method, the image to be watermarked is divided into blocks in a multi-level hierarchy and calculating block digital signatures in thus hierarchy. At each level of the hierarchy, a digital signature for each block is calculated using the seven most significant bit(MSBs)-plane values of all pixels within the block. And the resulting signature is incorporated into the LSBs of selected pixels within the block. We provide experimental results to demonstrate the effectiveness of the proposed method.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.759-763
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• 2004

While the needs for VoIPs(Voice over IP) encourage the commercial trials for VoIP services, there are many problems such as user authentication, blocking of illegal user and eavesdropping. In this paper, a management algorithm of registration of VoIP terminals is explained and security methods for tolling and data encryption module is designed and built up. The module structure will have the advantages of the entire development of secured gatekeeper without whole modification of gatekeeper. In order to secure the ordinary gatekeeper based on H.323 standard, user authentication and data encryption technologies are developed based on the H.235 standard and simply located over the plain H.323 stacks. The data structures for secured communications are implemented according to ASN.1 structures by H.235.

• Convergence Security Journal
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• v.14 no.6_1
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• pp.147-155
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• 2014

Encryption and authentication system in National Defense is divided into three system; KMI, MPKI, and GPKI. In this paper, we report inherent problem and security threaten in MPKI and propose an attribute-based authentication scheme using attribute-based signature in order to improve user authentication. In our scheme, access structure is used by Monotone Span Program, and system server provides service after user authentication.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.948-950
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• 2002

IPSec authentication provides support for data integrity and authentication of IP packets. Authentication is based on the use of a message authentication code(MAC). Hash function algorithm is used to produce MAC , which is referred to HMAC. In this paper, we propose a cryptographic accelerator using FPGA implementations. The accelator consists of a hash function mechanism based on MD5 algorithm, and a public-key generator based on a Elliptiv Curve algorithm with small scale of circuits. The accelator provides a messsage authentification as well as a digital signature. Implementation results show the proposed cryptographic accelerator can be applied to IPSec authentications.