• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.4
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• pp.753-773
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• 2019

CV(Connected Vehicle) technology provides safety-related services and user convenience-related services to vehicle. Safety-related services can cause privacy problem by continuously transmitting vehicle information to nearby vehicles or base stations. Therefore, safety-related services should provide vehicle anonymity for privacy protection. However, if convenience-related services such as payment services fail to provide vehicle anonymity, driver information related to safety-related services may also be leaked. In this paper, we design a payment protocol based on ECQV(Elliptic Curve Qu-Vanstone) impicit certificate and group signature that provides BU-anonymity and traceability. The proposed payment protocol makes it impossible to track vehicles from payment transactions history by separating roles of payment system components. Moreover, we define the security requirements that the vehicle payment protocol must satisfy and show that the protocol satisfies the requirements.

• Journal of the Korea Society of Computer and Information
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• v.27 no.6
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• pp.77-86
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• 2022

Recently, various cryptocurrencies (coins) based on block chains have appeared, and interest in privacy coins, which is an anonymity-based cryptocurrency that values personal information protection, is growing. In this paper, we look at coin abuse cases using privacy coins, and analyze the technology that guarantees the anonymity of 8 mainly traded privacy coins (Monero, Dash, Zcash, BEAM, Grin, Horizen, Verge, and Pirate Chain). We would like to analyze the applied technologies for We present the problems that can occur in these privacy coins, check the technology and each element applied to the privacy coin, and analyze the technical difficulty of the anonymity guarantee technology for the mainly traded coins through this, and Appropriate countermeasures and classification of privacy coins for technical difficulty were presented through the problem. Through this, the standard for re-evaluating the value of the coin according to the application of appropriate technology for the privacy coin can be presented.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.93-101
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• 2023

In this paper, as a result of analyzing the TMIS authentication protocol using ECC and biometric information proposed by Chen-Chen in 2023, there were security problems such as user impersonation attack, man-in-the-middle attack, and user anonymity. Therefore, this paper proposes an improved authentication protocol that provides user anonymity to solve these problems. As a result of analyzing the security of the protocol proposed in this paper, it was analyzed to be secure for various attacks such as offline password guessing attack, user impersonation attack, smart-card loss attack, insider attack, perfect forward attack. It has also been shown to provided user privacy by guaranteeing user anonymity and untraceability, which must be guaranteed in TMIS. In addition, there was no significant increase in computational complexity, so the efficiency of execution time was achieved. Therefore, the proposed protocol in this paper is a suitable user authentication protocol for TMIS.

• 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 Information Processing Systems
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• v.9 no.2
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• pp.247-258
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• 2013

A new secure network communication technique that has been designed for mobile wireless services, is presented in this paper. Its network services are mobile, distributed, seamless, and secure. We focus on the security of the scheme and achieve anonymity and reliability by using cryptographic techniques like blind signature and the electronic coin. The question we address in this paper is, "What is the best way to protect the privacy and anonymity of users of mobile wireless networks, especially in practical applications like e-commerce?" The new scheme is a flexible solution that answers this question. It efficiently protects user's privacy and anonymity in mobile wireless networks and supports various applications. It is employed to implement a secure e-auction as an example, in order to show its advantages in practical network applications.

• International Journal of Contents
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• v.7 no.4
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• pp.35-43
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• 2011

USN is a technology to detect human external environment. It is an important factor in buildinga ubiquitous computing environment. In this thesis, an authentication method was proposed to allow the sensor nodes, which have weak computing operation capability, to safely communicate with each other in USN and guarantee the anonymity of users for their privacy. In the proposed authentication method that takes into account the characteristics of sensor network, sensor nodes based on a symmetric key algorithm do not transfer keys directly, instead, they mix the random numbers received from AS to generate keys necessary for communications, having a master key and a pseudo-random number generator.In addition, in this thesis, TA was adopted to minimize the leakage of users' information, and a scheme through which virtual IDs received from AS are delivered to sensor nodes was applied to improve anonymity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.388-395
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• 2009

Three-party authenticated key exchange protocol based on smartcards using XOR and hash function operation instead of the public key operation has been proposed in 2006. Recently, it is doing for research because of increasing interest in privacy. This paper pointed out that proposed three-party authenticated key exchange protocol in 2006 has some problems; it is user anonymity and slow wrong input detection, and then we proposed new one to overcome these problems.

• The Journal of the Korea Contents Association
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• v.9 no.2
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• pp.36-42
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• 2009

In 2005, Chien and Chen proposed a remote user authentication scheme for preserving user anonymity to conquer some problems Das et. al. schemes have. In 2007, Hu et. al. pointed out that their scheme have some problems. Therefore, they proposed a new one and claimed that their scheme overcome all of these problems. However, We will show that Hu et. al. scheme still hold some problems; it cannot resist to denial of service attack and protect the user anonymity. Hence, we propose ours and demonstrate our scheme conquer these problems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.11C
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• pp.1023-1029
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• 2006

In this Paper, we present a novel authentication and key exchange(AKE) protocol for inter-NSP(provider) roaming in IEEE 802.16e networks. The proposed protocol allows performing both user and device authentication jointly by using two different authentication credentials and Provides user anonymity and session key establishment. Also, this protocol requires only two round number message exchange between foreign network and home network.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.7
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• pp.839-846
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• 1999

전자상거래에서 중요한 지불 수단으로 떠오르고 있는 전자화폐 시스템에 있어서 사용자에의 익명성 제공은 기존의 지불 시스템에서 제공하지 못하는 중요한 요소이다. 그러나 사용자 익명성을 악용하여 각종 범죄 활동에 이용하려는 시도가 발생할 수 있으며 전자화폐 시스템 도입시 이에 대한 대책도 함께 강구되어야 한다. 따라서 본 논문에서는 전자화폐의 효율적 사용을 위해 분할성 기능과 함께 화폐 추적과 사용자 추적 기능을 제공하는 효율적인 전자화폐 프로토콜을 제안한다.Abstract Electronic Cash System is an important payment method in Electronic Commerce. The anonymity of users is an important issue in such systems, but the issue has not been addressed by previous payment methods. User anonymity can lead to a system that is vulnerable to various criminal activities. Therefore, e-cash systems must consider ways to prevent such criminal activities. In this paper we suggest an efficient e-cash system that eliminates the vulnerability of the system by using the divisible ability of the system with the coin and owner tracing.