• Journal of the Korea Computer Industry Society
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• v.2 no.12
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• pp.1541-1548
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• 2001

In this paper, We propose a new Kerberos certification mechanism that improve certification service based on PKINIT that announce in IETF CAT Working Group. Certification between area connected by chain through PKINIT that use X.509 and DS/DNS mutually for service. In order to provide regional services used private key and public key, X.509 of PKINIT is employed on session part and Kerberos's private key on actual authentication part. New mechanism be reduced communication overload doing to simplify certification formality between Client and remote KDC by KDC's certificate use to get ticket in remote sacred ground and remote KDC's reaffirmation process omitted.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.2
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• pp.139-144
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• 2007

Due to the increasing use of Internet and spread of ubiquitous environment the security of private information became an important issue. For this reason, many suggestions have been made in order to protect the privacy of users. In the study of authentication system using a smart card which is one of the methods for protecting private information, the main idea is to offer user anonymity. In 2004, Das et al. suggested an authentication system that guarantees anonymity by using a dynamic ID for the first time. However, this scheme couldn't guarantee complete anonymity as the identity of the user became revealed at log-in phase. In 2005, Chien at al. suggested a authentication system that guarantees anonymity, but this was only safe to the outsider(attacker). In this paper, we propose a scheme that enables the mutual authentication between the user and the sewer by using a smart card. For the protection of the user privacy, we suggest an efficient user authentication system that guarantees perfect anonymity to both the outsider and remote server.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.4
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• pp.125-134
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• 2018

Lamport firstly suggested password base authentication scheme and then, similar authentication schemes have been studied. Due to the development of Internet network technology, remote user authentication using smart card has been studied. Li et al. analyzed authentication scheme of Chen et al. and then, Li et al. found out the security weakness of Chen et al.'s scheme such forward secrecy and the wrong password login problem, and proposed an a new smart card based user password authentication scheme. But Liu et al. found out that Li et al.'s scheme still had security problems such an insider attack and man-in-the-middle attack and then Liu et al. proposed an efficient and secure smart card based password authentication scheme. This paper analyzed Liu et al.'s authentication and found out that Liu et al.'s authentication has security weakness such as no perfect forward secrecy, off-line password guessing attack, smart-card loss attack, and no anonymity. And then, this paper proposed security enhanced efficient smart card based password authentication scheme using fuzzy extraction technology.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.273-278
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• 2013

Recently, user authentication schemes using smart cards for multi-server environment have been proposed for practical applications. In 2009, Liao-Wang proposed a secure dynamic ID based remote user authentication scheme for multi-server environment that can withstand the various possible attacks and provide user anonymity. In this paper, we analyze the security of Liao-Wang's scheme, and we show that Liao-Wang's scheme is still insecure against the forgery attack, the password guessing attack, the session key attack, and the insider attack. In addition, Liao-Wang's scheme does not provide user anonymity between the user and the server.

• Journal of the Korea Society of Computer and Information
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• v.17 no.11
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• pp.83-91
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• 2012

Authentication schemes preserving user anonymity have first been proposed by Das et al, and most of user anonymity schemes provide user anonymity against outside attacks in the communication channel. In this paper, according to the increasing of personal information exposure incidents by server attack, we propose a new authentication scheme that provides user anonymity against server as well as one against outside attacks in the communication channel. Furthermore, the proposed authentication scheme provides traceability that remote server should be able to trace the malicious user and it also solves the problem of increasing computational load of remote server by solving weakness of wrong password input by mistake.

• Journal of the Korea Society of Computer and Information
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• v.15 no.12
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• pp.109-116
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• 2010

Due to the increasing interest and demands of user privacy, remote user authentication schemes using smart card has been researched in active. Recently, a lot of suggestion have been made in order to provide user's anonymity and trace a malicious user. In 2008, Kim et al. proposed a traceable anonymity authentication scheme. In 2009, Choi et al. pointed out that Kim's protocol was insecure against outsider attacker and proposed an improved scheme. But Kim's and Choi's schemes fail to provide the user's anonymity or compute some values in the protocol. In this paper, we analyse those problems and suggest two improved schemes to resolve those problems.

• Convergence Security Journal
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• v.23 no.4
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• pp.3-15
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• 2023

As remote services and remote work become commonplace, the use of the Metaverse has grown. This allows transactions like real estate and finance in virtual Second Life. However, conducting economic activities in the Metaverse presents unique security challenges compared to the physical world and conventional cyberspace. To address these, the paper proposes solutions centered on authentication and privacy. It suggests improving data preprocessing based on Metaverse data's uniqueness and introduces a new authentication service using NFTs while adhering to W3C's DID framework. The system is implemented using Hyperledger Indy blockchain, and its success is confirmed through implementation analysis.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.95-98
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• 2004

In this paper, we propose policy-based authentication framework which consists of policy server, CA and a policy language designed for ubiquitous environments. Using policies allows the security functionality to be modified without changing the implementation of the entities involved. Policy-based authentication framework needs to be very expressive but lightweight and easily extensible. We propose the feasibility of our policy language and policy-based authentication framework in ubiquitous-environment through a prototype and solve the problem that traditional framework have a simple registration and authentication to provide dynamic service.

• International Journal of Contents
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• v.8 no.3
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• pp.79-82
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• 2012

In digital contents distribution environments, a user authentication is an important security primitive to allow only authenticated user to use right services by checking the validity of membership. For example, in Internet Protocol Television (IPTV) environments, it is required to provide an access control according to the policy of content provider. Remote user authentication and key agreement scheme is used to validate the contents accessibility of a user. We propose a novel user authentication scheme using smart cards providing a secure access to multimedia contents service. Each user is authenticated using a subset of attributes which are issued in the registration phase without revealing individual's identity. Our scheme provides the anonymous authentication and the various permissions according to the combination of attributes which are assigned to each user. In spite of more functionality, the result of performance analysis shows that the computation and communication cost is very low. Using this scheme, the security of contents distribution environments in the client-server model can be significantly improved.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.3
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• pp.50-57
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• 2016

In 2013, Li et al. proposed an improved smart card-based remote user password authentication scheme, and claimed that their scheme not only overcomes security weaknesses of the Chen et al.'s scheme but also is a more user friendly scheme compared with other schemes. In this paper, we analyze the security of Li et al.'s authentication scheme and we show that Li et al.'s authentication scheme is still insecure against the various attacks, such as the off-line password guessing attack, the forgery attack, and the session key generation attack etc. Also, we propose an improved scheme that can resist these security drawbacks of Li et al.'s authentication, even if the secret information stored in the smart card is revealed. As a result of security analysis, the improved scheme is relatively more secure against several attacks than other related schemes in terms of the security.