• Journal of KIISE:Computer Systems and Theory
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• v.29 no.5
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• pp.299-306
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• 2002

Partially blind signature scheme is used in applications such as electronic cash and electronic voting where the privacy of the signature requester is important. This paper proposes an RSA-based enhanced partially blind signature scheme minimizing the amount of computation of the signature requester. The signature requester needs computation in blinding the message to the signer and in generating the final signature using the intermediate signature generated by the signer. Since the proposed scheme enables the signature requester to get the final signature just by using modular additions and multiplications, it decreases computation of the signature requester considerably. So, the proposed partially blind signature scheme is adequate for devices such as mobile device, smart-card, and electronic purse that have relatively low computing power.

• Journal of Information Processing Systems
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• v.19 no.3
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• pp.334-346
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• 2023

An electronic document based on PDF has been widely used in customer communication between an enterprise and a customer to deliver personalized content. However, electronic documents based on PDF in the form of paper layouts are not suitable for mobile environments because of low readability and lack of interactive interaction. Even though HTML is an essential language in a mobile environment, electronic document based on PDF is still used as it has a content integrity verification feature with a digital signature. It means that a user is sacrificing user experience in a mobile environment for content integrity and using paper-layout electronic documents. In this research, we design the Document HTML specification by setting the Document HTML conformance, adding the extended meta tags, and signing the message digest with a digital signature based on public key infrastructure (PKI). Furthermore, we implemented the Document HTML system, which has REST API services to generate and verify the Document HTML, and did experimental verification of the theory. As a result, we have confirmed that the Document HTML has both content integrity and user experience on mobile. Furthermore, the Document HTML is expected to be an alternative document format to deliver personalized content from an enterprise to a customer in a mobile environment instead of the paper layout electronic document such as PDF.

• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.1
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• pp.166-183
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• 2013

It requires a lot of costs and manpower to manage an election. The electronic voting scheme can make the election system economic and trustful. The widespread use of smart phones causes mobile voting to be a major issue. The smart phone can be used as a mobile voting platform since it can carry out many services in addition to basic telephone service. To make mobile voting practical and trustful, we analyzed two subjects of study. Firstly, the way to make a biometric based mobile ID, which has legal binding forces. In mobile voting, user identification is accomplished on line since the voter should be able to vote wherever they go. The digital ID conducts a similar role to the need for a resident card. The user's identity is bound to the resident card legally. To bind the user's identity to the smart phone, we use USIM. Biometric recognition is also needed to authenticate the user, since the user cannot prove him or her on line face-to-face. The proposed mobile ID can be reissued by means of introducing a random secret value. Secondly, the mobile voting scheme is proposed where candidates can accept election results without doubt. The goal of an election is to select a leader among two or more candidates. Existing electronic voting schemes mainly focus on the study of ballot verification accomplished by voters. These approaches are not safe against collusion attacks where candidates and the election administration center are able to collude to fabricate election results. Therefore, a new type of voting and counting method is needed where candidates can directly take part in voting and counting stages. The biometric based multi-signature scheme is used to make the undeniable multi-signed ballot. The ballot cannot be verified without the help of all candidates. If candidates accept election results without a doubt, the fairness of the election is satisfied.

• The KIPS Transactions:PartC
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• v.10C no.5
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• pp.533-540
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• 2003

According to the development of mobile communications, many people have been offered high qualify of the application services using portable terminals. But those works nay have many vulnerabilities and have the limit of excutaions. Because the application services are provided in mobile network and the performance of portable terminals is lower than that of base stations. To improve these problems, in this paper, we propose one-time proxy signature scheme that can reduce the computational ctsost on a user and prevent a proxy agent's dishonesty. The proposed scheme is based on the KBLK scheme [2] which applied the fail-stop signature scheme [1]. It is constructed that a proxy signer can sign only one message with a proxy key and we add anonimity to it for the user's identity protection in mobile communication like a M-commerce.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.229-232
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• 2008

본 논문에서는 방송프로그램 저작권 식별관리를 위한 방송프로그램의 Video Signature와 국가표준콘텐츠식별 체계인 UCI(Universal & Ubiquitous Content Identifier)와의 연계 방안을 제시한다. Video Signature는 UCI와 같은 식별자의 인위적인 부여 과정이 없더라도 비디오 콘텐츠 자체에서 직접 특징정보를 추출할 수 있기 때문에, 이미 배포 유통된 콘텐츠에 대해서도 식별 확인이 가능하다. 따라서, 본 연구에서는 UCI 표준식별체계와 방송프로그램의 Video Signature와의 지속적인 연계를 위하여, 바이너리로 표현된 Video Signature가 포함된 UCI 응용 메타데이터를 정의한다. 그리고 UCI 표준식별체계 기반의 Video Signature 전송 및 관리 메카니즘에 기반한 방송프로그램의 저작권 식별관리 시나리오를 제시한다.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.131-134
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• 2002

As the increased use of computer, wired/wireless/mobile Internet, security in using Internet becomes a more important problem. Thus, biometric technology using physical and behavior characteristics of a person is hot issue. Many different types of biometric technologies of a person such as fingerprint, face, iris, vein, DNA, brain wave, palm, voice, dynamic signature, etc. had already been studied but remained unsuccessful because they do not meet social demands. However, recently many of these technologies have been actively revived and researchers have developed new products on various commercial fields. Dynamic signature verification technology is to verify the signer by calculating his writing manner, speed, angle, and the number of strokes, order, the down/up/movement of pen when the signer input his signature with an electronic pen for his authentication. Then signature verification system collects mentioned above various feature information and compares it with the original one and simultaneously analyzes to decide whether signature is forgery or true. The prospect of signature verification technology is very promising and its use will be wide spread in terms of economy, security, practicality, stability and convenience.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.1003-1019
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• 2019

Threshold ring signature scheme enables any t entities from N ring members to spontaneously generate a publicly verifiable t-out-of-N signature anonymously. The verifier is convinced that the signature is indeed generated by at least t users from the claimed group, but he cannot tell them apart. Threshold ring signatures are significant for ad-hoc groups such as mobile ad-hoc networks. Based on the lattice-based ring signature proposed by Melchor et al. at AFRICRYPT'13, this work presents a lattice-based threshold ring signature scheme, employing the technique of message block sharing proposed by Choi and Kim. Besides, in order to avoid the system parameter setup problems, we proposed a message processing technique called "pad-then-permute", to pre-process the message before blocking the message, thus making the threshold ring signature scheme more flexible. Our threshold ring signature scheme has several advantages: inherits the quantum immunity from the lattice structure; has considerably short signature and almost no signature size increase with the threshold value; provable to be correct, efficient, indistinguishable source hiding, and unforgeable.

• Journal of Information Processing Systems
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• v.9 no.3
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• pp.461-476
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• 2013

Recently, smart devices for various services have been developed using converged telecommunications, and the markets for near field communication mobile services is expected to grow rapidly. In particular, the realization of mobile NFC payment services is expected to go commercial, and it is widely attracting attention both on a domestic and global level. However, this realization would increase privacy infringement, as personal information is extensively used in the NFC technology. One example of such privacy infringement would be the case of the Google wallet service. In this paper, we propose an zero-knowledge proof scheme and ring signature based on NTRU for protecting user information in NFC mobile payment systems without directly using private financial information of the user.

• The Journal of Information Systems
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• v.12 no.1
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• pp.67-85
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• 2003

In the recent a mobile internet makes a change in internet business. The mobile internet service is resulting in M-commerce. Even if M-commerce provides only information service, there will be much possibilities to make applications in various areas such as, delivery service, trading service, banking service etc. in the near future. Delivery service requires many steps in processing, originally. This study is designed to implement a mobile system which makes short in delivery process. It includes that a delivery man receives a signature on a paper and input data at the delivered place by using PDA at hand. The mobile system will be contributed to shorten delivery speed. It is proposed to implement the mobile office system for improving service efficiency in the business of delivery service. This study is designed to implement a mobile system which make short in delivery process. It includes that a delivery man receives a signature on a paper and input data at the delivered place by using PDA at hand. The mobile system will be contributed to shorten delivery speed. It is proposed to implement the mobile office system for improving service efficiency in the business of delivery service.