• Spatial Information Research
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• v.20 no.4
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• pp.83-92
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• 2012

Location-based services (LBS) are increasingly popular due to the improvement of geo-positioning capabilities and wireless communication technology. However, in order to enjoy LBS services, a user requesting a query must send his/her exact location to the LBS provider. Therefore, it is a key challenge to preserve user's privacy while providing LBS. To solve this problem, the existing method employs a 2PASS cloaking framework that not only hides the actual user location but also reduces bandwidth consumption. However, 2PASS does not fully guarantee the actual user privacy because it does not take the real user distribution into account. Hence, in this paper, we propose a nearest neighbor query processing algorithm that supports K-anonymity property based on the weighted adjacency graph(WAG). Our algorithm not only preserves the location of a user by guaranteeing k-anonymity in a query region, but also improves a bandwidth usage by reducing unnecessary search for a query result. We demonstrate from experimental results that our algorithm outperforms the existing one in terms of query processing time and bandwidth usage.

• ETRI Journal
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• v.31 no.4
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• pp.460-462
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• 2009

The emerging wireless networks require the design of new authentication protocols due to their dynamic nature and vulnerable-to-attack structure. Recently, Wu and others proposed a wireless authentication protocol which is claimed to be an improvement of the authentication protocol proposed by Lee and others which provides user anonymity. In this letter, we show that these protocols have a common flaw and that these protocols fail to provide user anonymity. We also propose a modification method to solve this problem.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.2
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• pp.173-180
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• 2010

The research of the preserving privacy of sensitive information has been popular recently. Many researches about the techniques of generalizing records under k-anonymity rules have been done. Considering that data anonymity requires a lot of time and resources, it would be important to decide whether a table is vulnerable to privacy attacks before being opened in terms of the improvement of data utilization as well as the privacy protection. It is also important to check to which attack the table is vulnerable and which of anonymity methods should be applied in the table. This paper describe two possible privacy attacks based upon related references. Also, we suggest the technique to check whether data table is vulnerable to any attack of them and describe what kind of anonymity methods should be done in the table. The technique we suggest in this paper can also be applied for checking the safety of anonymity tables in which insert or delete operations occurred as well from privacy attacks.

• Journal of Engineering Education Research
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• v.12 no.3
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• pp.107-117
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• 2009

This research deals with the effects of anonymity and morality to the patterns of learner participation in the real-time online discussion. Based on these research results, it was suggested that the anonymity mode and morality levels subject should be utilized in order to enhance the participation quality of online discussion

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.757-764
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• 2001

The increase of electronic commerce leads to the increasing attention to the way customers pay and a large number of researches on payment system. Recently many researches on a system which provides anonymity in order to protect user\`s privacy have been carried out. And some potential problems from that system are being reviewed by anonymity control system. This thesis will include the following. First, I want to analyze the old scheme related to divisible and examine general ideas of anonymity control. Second, I propose a new blind signature in addition to KCDSA, the standard digital signature in Korea. The last one I want to propose is a new electronic cash system with the divisible for more efficient use of electronic cash which can control anonymity with the help of trustee.

• The KIPS Transactions:PartC
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• v.18C no.4
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• pp.207-212
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• 2011

Vehicular Ad Hoc Network(VANET) is a communication technology between vehicles and vehicles(V2V) or vehicles and infrastructures(V2I) for offering a number of practical applications. Considering the importance of communicated information through VANET, data authentication, confidentiality and integrity are fundamental security elements. Recently, to enhance a security of VANET in various circumstances, message authentication is widely researched by many laboratories. Among of them, Zhang. et. al. is an efficient method to authenticate the message with condition of anonymity in dense space. In the scheme, to obtain the vehicular ID with condition of anonymity, the k-anonymity is used. However it has a disadvantage, which conducts hash operations in case of determining the vehicular ID. In the paper, we present a location based algorithm using received signal strength for the location based authentication and encryption technique as well, and to enhance the accuracy of algorithm we apply a location determination technique over the 3-dimensional space.

• Journal of the Korean Home Economics Association
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• v.49 no.2
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• pp.63-74
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• 2011

Tension and self-control are explanatory factors in adolescent delinquency, and internet addiction and anonymity are regarded as factors underlying cyber deviation. The aim of this study was to investigate the interrelationships between these factors and cyber deviation. Participants were 485 middle and high school students in the Jeonbuk region. The results showed that tension and self-control were predictors of cyber deviation and that internet addiction was a mediating variable for both the predictors. Anonymity was found to have a mediating role, but only in respect of the tension-cyber deviation pathway. These findings suggested a number of implications. Firstly, the educational programs on cyber deviation should be different from the existing deviation prevention programs. Secondly, measures to prevent internet addiction are needed for the effective prevention of cyber deviation. Lastly, the finding of a relationship between anonymity and cyber deviation indicates the need to adopt a long-term perspective drawing on values education techniques to develop a code of cyber space ethics for "netizens".

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.5
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• pp.2407-2426
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• 2016

A group signature scheme allows any member to sign on behalf of a group. It is applied to practical distributed security communication environments, such as privacy-preserving, data mining. In particular, the excellent features of group signatures, including membership joining and revocation, anonymity, traceability, non-frameability and controllable linkability, make group signature scheme more attractive. Among these features, non-frameability can guarantee that a member's signature cannot be forged by any other (including issuer), and controllable linkability supports to confirm whether or not two group signatures are created by the same signer while preserving anonymity. Until now, only Hwang et al.'s group schemes (proposed in 2013 and 2015) can support all of these features. In this paper, we present a new dynamic group signature scheme which can achieve all of the above excellent features. Compared with their schemes, our scheme has the following advantages. Firstly, our scheme achieves more efficient membership revocation, signing and verifying. The cost of update key in our scheme is two-thirds of them. Secondly, the tracing algorithm is simpler, since the signer can be determined without the judging step. Furthermore, in our scheme, the size of group public key and member's private key are shorter. Lastly, we also prove security features of our scheme, such as anonymity, traceability, non-frameability, under a random oracle model.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.266-269
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• 2002

As a simulation or replacement of analog money in cyber space, the e-cash was introduced by using cryptographic primitives. Since a perfect anonymity system causes some illegal activities, such as money laundering, blackmailing, and illegal purchase, a revocable electronic system was paid a great attention to control the anonymity. In general, Trust Third Party(TTP) is introduced to detect any dubious user and coin, namely user tracing and coin tracing. In this paper we propose a new revocable anonymity e-cash system, and verify the security requirement as well. In our scheme a user first withdraws the e-coin from bank by using blind signature, and then TTP verifies the bank's signature and records the tracing information.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.22 no.2
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• pp.103-111
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• 2011

Objectives : This study compared covert narcissistic propensity in adolescents with internet addiction tendency to normal adolescents. Further, we investigated the correlation between such propensities and anonymity in cyberspace, presence feeling and interactivity in internet gaming, and achievement motivation in adolescents with internet addiction tendencies. Methods : Male middle school students with internet addiction tendencies (Addiction Tendency Group, N=27) and normal students (Control Group, N=29) were recruited. The scale of internet use, Covert Narcissism Scale, scale of achievement motivation, scale of anonymity in cyberspace, scale of presence feeling in internet games, and the scale of interactivity in internet games were administered. A comparison of the average scores and correlation analyses were performed. Results : 1) Compared with Control Group, the Addiction Tendency Group showed significantly higher scores on all subscales of the Covert Narcissism Scale, and both the scale of presence feeling and that of interactivity in internet games. Further, the score on the scale of achievement motivation for the Addiction Tendency Group was significantly lower than that of the Control Group. 2) In the Addiction Tendency Group, the scores on several subscales of the Covert Narcissism Scale were significantly positively correlated with the scores on the scale of presence feeling in internet games, anonymity in cyberspace, and interactivity in internet games. However, in the Control Group, the scores of several subscales on the Covert Narcissism Scale were significantly negatively correlated with the score on the scale of achievement motivation, and was significantly positively correlated with the score on the scale of interactivity in internet games. There were no other significant correlations between the scores on the subscales of the Covert Narcissism Scale and the scores of either presence feeling in internet games or anonymity in cyberspace. Conclusion : These results suggested that adolescents with a tendency to be addicted to the internet exhibited higher covert narcissistic propensities than normal adolescents and that the covert narcissistic tendencies were related with presence feeling in cyber games as well as with anonymity in cyberspace.