• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.4
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• pp.11-26
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• 2011

The existing anonymous authentication schemes based on group signatures for protecting privacy do not provide anonymous authorization which is required in the practical environments. In this paper, we propose an anonymous authentication and authorization scheme that enables a service provider both to authenticate anonymously its users and to provide different service according to their authorization. In the proposed scheme, a user's real identity, anonymity and authorization are managed distinctly through the separation of group manager's capabilities and an authorization authority. It is also possible for the proposed scheme to apply various access control models.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.5
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• pp.181-195
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• 2011

There's a controversy about an invasion of privacy which includes a leakage of private information and linking of user's behavior on internet. Although many solutions for this problem are proposed, we think anonymous authentication, authorization, and payment mechanism is the best solution for this problem. In this paper, we propose an effective anonymity-based method that achieves not only authentication but also authorization. Our proposed method uses anonymous qualification certificate and group signature method as an underlying primitive, and combines anonymous authentication and qualification information. An eligible user is legitimately issued a group member key pair through key issuing process and issued some qualification certificates anonymously, and then, he can take the safe and convenience web service which supplies anonymous authentication and authorization. The qualification certificate can be expanded according to application environment and it can be used as payment token.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3C
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• pp.293-298
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• 2008

Recently, with the development of mobile techniques and the consideration to conveniency of using, the research on Mobile RFID Reader technique is getting more and more attentions. Until now, all security authentication algorithms of RFID are algorithms about range between Tag and Reader. The range between Reader and backend DB is composed by wired networks, so it's supposed to be secure range. But it must be taken account of the problem of information security and privacy in wireless range during the design of Mobile RFID Reader. In this paper we design an blind signature scheme based on weil-paring finite group's ECC encryption scheme, and by using this blind signature we propose the anonymous authorization scheme to Mobile RFID Reader's users.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.4 s.304
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• pp.25-32
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• 2005

The spread of mobile devices, PDAs and sensors has enabled the construction of ubiquitous computing environments, transforming regular physical spaces into 'Smart space' augmented with intelligence and enhanced with services. However, the deployment of this computing paradigm in real-life is disturbed by poor security, particularly, the lack of proper authentication and authorization techniques. Also, it is very important not only to find security measures but also to preserve user privacy in ubiquitous computing environments. In this Paper, we propose efficient user authentication and authorization model with anonymity for the privacy-preserving for ubiquitous computing environments. Our model is suitable for distributed environments with the computational constrained devices by using MAC-based anonymous certificate and security association token instead of using Public key encryption technique. And our Proposed Protocol is better than Kerberos system in sense of cryptographic computation processing.

• Journal of Internet Computing and Services
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• v.18 no.2
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• pp.1-11
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• 2017

There are two kinds of wireless network access to a certain place by using smart devices - 1) open (anonymous) - access and 2) user-authorized access. The open-access is a non-authorization connection method which does not need to require Smart device's user authorized information. It means open-access use only user's SSID (Service Set Identifier) information to access the wireless AP devices following public wireless network standard. This access mechanism is not suitable to use all of public wireless networks because users have to get all wireless network information around them. As a result, huge data for smart devices should be one of the most critical overload problems for them. Secondly, the user-authorized access method uses wireless network information (SSID and password) chosen by the users. So, the users have to remember and use the network access information data manually whenever accessing the network. Like open-access, this access method also has the operational and inconvenient problem for the users - manually inputting access information whenever connecting to the network. To overcome this problem in both schemes, we propose two improved wireless network access methods: 1) the implementation of automatic AP connection mechanism using user-authorization and iBeacon messages, and 2) SSID registration form for public wireless networks.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.543-551
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• 1997

Many areas of human activities are computerized with the wide spread use of computers and communication networks.Electrinic voting is an important social activity in democtatic society.The realization of electronic democracy is based on the sectrity of edectronic voting scheme.Therefore, it is necessary to use the cryto-graphic technique for secure electronic voting scheme.Therefore, it is necessary to use the cryto-graghic technique for secure election.In this stusy, an dedctronic voting scheme sutiable for large election is proposed.In order to make practi-cal volting scheme, we assume that the voting authorization center is trustful and the chaum's anonymous com-munication channel[6] prepared before the election day.The center authorizes the ballot of eligible voter by using the ID based digital signature scheme in the registeation stage.During the voting stage, undeniable chal-lenge/ response prorocol is performed between the center and the boters to ensure that the intemediate voting results should not affect the entire.The proprsed scheme fully conforms to the requirments of large scale election such as privacy of the voters, fairness, unresuability, unforgeability and eligbility.