• 한국해양학회지
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• v.29 no.3
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• pp.319-323
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• 1994

An ocean data distribution system developed using anonymous FTP is introduced. Moreover for beginners, some basic concepts and computational environment necessary for use of the system, and actual examples are also shown.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.1
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• pp.287-304
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• 2022

With the development of quantum computers, ring signature schemes based on large integer prime factorization, discrete logarithm problem, and bilinear pairing are under threat. For this reason, we design a ring signature scheme based on lattice with a fixed verification key. Compared with the previous ring signature scheme based on lattice, our design has a fixed verification key and does not disclose the signer's identity. Meanwhile, we propose an anonymous electronic voting scheme by using our ring signature scheme based on lattice and (t, n) threshold scheme, which makes up for the lack of current anonymous electronic voting that cannot resist attacks of the quantum computer. Finally, under standard model (SM), we prove that our ring signature scheme based on lattice is anonymous against the full-key exposure, and existentially non-forgeable against insider corruption. Furthermore, we also briefly analyze the security of our anonymous electronic voting scheme.

• Proceedings of the Korea Society of Design Studies Conference
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• 2002.11b
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• pp.36-37
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• 2002

• The KIPS Transactions:PartC
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• v.16C no.5
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• pp.589-596
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• 2009

Until now, some protocols have been presented to provide vehicle's anonymity and unlinkability in VANET by means of issuing multiple anonymous certificates to each vehicle from the trust authority, or shot-time anonymous certificate to a vehicle after mutual authentication between a Roadside Unit (RSU) and the vehicle. However, these protocols have high overheads of the trust authority, RSUs and vehicles for generating anonymous certificate. In this paper, we propose an efficient anonymous authentication protocol, in which RSUs can issue multiple shot-time anonymous certificates to a vehicle to alleviate system overheads for mutual authentication between vehicles and RSUs. Several simulations are conducted to verify the efficiency of the proposed protocol in terms of RSU valid serve ratio and vehicle's computational costs. Moreover, the proposed protocol provides unlinkability and traceability when multiple RSUs are compromised, whereas previous protocols do not provide unlinkability and traceability.

• Journal of Information Science Theory and Practice
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• v.6 no.3
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• pp.25-36
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• 2018

Anonymity plays an increasingly important role on social media. This is reflected by more and more applications enabling anonymous interactions. However, do social media users behave different when they are anonymous? In our research, we investigated social media services meant for solely anonymous use (Jodel) and for widely spread non-anonymous sharing of pictures and videos (Instagram). This study examines the impact of anonymity on the behavior of users on Jodel compared to their non-anonymous use of Instagram as well as the differences between the user types: producer, consumer, and participant. Our approach is based on the uses and gratifications theory (U>) by E. Katz, specifically on the sought gratifications (motivations) of self-presentation, information, socialization, and entertainment. Since Jodel is mostly used in Germany, we developed an online survey in German. The questions addressed the three different user types and were subdivided according to the four motivation categories of the U>. In total 664 test persons completed the questionnaire. The results show that anonymity indeed influences users' usage behavior depending on user types and different U> categories.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.968-988
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• 2010

Anonymous hierarchical identity based encryption (HIBE) is an extension of identity based encryption (IBE) that can use an arbitrary string like an e-mail address for a public key, and it additionally provide the anonymity of identity in ciphertexts. Using the anonymous HIBE schemes, it is possible to construct anonymous communication systems and public key encryption with keyword search. This paper presents an anonymous HIBE scheme with constant size ciphertexts under prime order symmetric bilinear groups, and shows that it is secure under the selective security model. Previous anonymous HIBE schemes were constructed to have linear size ciphertexts, to use composite order bilinear groups, or to use asymmetric bilinear groups that is a special type of bilinear groups. Our construction is the first efficient anonymous HIBE scheme that has constant size ciphertexts and that uses prime order symmetric bilinear groups. Compared to the previous scheme of composite order bilinear groups, ours is ten times faster. To achieve our construction, we first devise a novel cancelable random blinding technique. The random blinding property of our technique provides the anonymity of our construction, and the cancellation property of our technique enables decryption.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.6175-6189
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• 2019

To slove the security and efficiency problem of anonymous authentication in vehicular ad-hoc network (VANET), we adopt the bilinear pairing theory to propose an identity-based batch anonymous authentication scheme for VANET. The tamper-proof device in the on-board unit and the trusted authority jointly realize the anonymity of vehicle identity and the signature of messages, which further enhances the security of this scheme, as well as reduces the overhead of trusted authority. Batch authentication can improve the efficiency of anonymous authentication for VANET. Security and efficiency analyses demonstrate that this scheme not only satisfies such security properties as anonymity, non-forgeability and non-repudiation, but also has advantage in time and space complexity. Simulation results show that this scheme can achieve good performance in real-time VANET communication.

• 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.

• Asia pacific journal of information systems
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• v.30 no.3
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• pp.497-512
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• 2020

Anonymity is one of the key factors that influence communication and the work behaviours of people. It is even more evident in an online community where the role of anonymity can be akin to a double-edged sword: it can increase participation while at the same time having detrimental effects due to irresponsible and disruptive behaviour. Most studies on anonymous participation in groups or communities have reported this ambivalent view of anonymity: positive or negative. Furthermore, the effects of anonymous participation may be different in a dynamic sense because the task characteristics of participation can vary across time. In this study, we hypothesise that the effects of anonymity in online collaboration differ across the stages of collaboration. We analysed 2,978 featured articles on the English-language Wikipedia website and investigated the contributions of anonymous participants. While the contributions of anonymous participants were negative to collaboration efficiency as a whole, the negative effect of anonymous participants was stronger in the earlier stage than the later stage of collaboration. These findings indicate that the effect of anonymity has two sides in terms of collaboration efficiency in the same collaborative environment.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.1
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• pp.108-117
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• 1997

The purpose of this study is to evaluate the demographic characteristics, alcohol-related characteristics and personality trends in the participants of Alcoholics Anonymous. We compared the 33 participants of Alcoholics Anonymous maintaining abstinence at least over 6 months with 35 hospitalized alcoholic patients who have never attended Alcoholics Anonymous and 32 normal controls. The personality trend was measured by Catell's 16 Personality Factors Questionnaire. -Korean Version. The results were as follows: 1) In the demographic data, the participants of Alcoholics Anonymous were mainly 40's, graduated from high school, married, unemployed, middle class in economic state, first or second sons. 2) In alcohol related characteristics, age of first drinking was mainly distributed from 15 to 19 years-old. The most common psychosocial and environmental problem as precipitating factor of alcohol consumption was the problem with primary supper group and the second one was occupational. Most of them drank everyday, and admitted one time. 3) In the first stratum sources traits, the participants of Alcoholics Anonymous demonstrated significantly higher score than hospitalized alcoholic Patients, but lower than normal control in C-factor(stableness). They demonstrated significantly higher score than hospitalized alcoholic patients and normal controls in O-factor(Guilt-proness) and demonstrated significantly higher score than hospitalized alcoholic patients in Q3-factor(self-control). 4) In the second stratum sources traits, they demonstrated significantly higher score than hospitalized alcoholic patients in EXT-factor(extroversions), and lower score than hospitalized alcoholic patients and normal controls in IND-factor(independence).