• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.161-170
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• 2005

The Certificate Revocation List(CRL) or the Online Certificate Status Protocol(OCSP)has been used to validate certificates. However, the CRL cannot validate certificates in realtime because of the Time-Gap problem and the OCSP server overloads in a large scale secure system. In addition, the client cannot access a wired LAN until the client has been authenticated by the authentication server on the IEEE 802. 1x framework. Therefore, the client cannot validate the authentication server's certificate using a certificate validation server. Thus, the client cannot authenticate the authentication server in realtime. To solve these problems this paper designed a secure system that can protect the content of communications and authenticate users in realtime on a wireless LAN The designed certificate validation protocol was proved that the stability and efficiency of the system was very high, the result of the validation had the presence, the speed of the validation was not affected by the system scale, the number of authorities user must trust was reduced to one, and the overload of the validation server was Protected. And the designed user authentication and key exchange protocols were Proved that the mutual authentication was possible in realtime and the fact of the authentication could be authorized by the CA because of using the authorized certificates.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.227-228
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• 2010

Generated One-Time Password (OTP) is used only once. This attributes is to safety than to repeated use the same password. Recently, Park's proposed on "Design of A One-time Password Generator on A Mobile Phone Providing An Additional Authentication for A Particular Transaction" use challenge-response based one-time password generator. However, Challenge exchange problem and currently OTP the same security level. In this paper, Park's proposed OTP generator design for us analysis. And then presents a resolution to the problem and new system logic. New system strong to Man-In-Middle attack and replay attack. In addition, OTP security level is higher.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.2
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• pp.417-429
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• 2019

WPA2-PSK uses a 4-way handshake protocol based on a shared secret to establish a secure session between a client and an AP. It has various security problems such as eavesdropping attacks and the secure session establishment process is inefficient because it requires multiple interactions between client and AP. The WPA3 standard has recently been proposed to solve the security problem of WPA2, but it is a small improvement using the same 4-way handshake methodology. OAuth 2.0 token authentication is widely used on the web, which can be used to keep an authenticated state of a client for a long time by using tokens issued to an authenticated client. In this paper, we apply the dual-token based randomized token authentication technology to the Wi-Fi security protocol to achieve an efficient Wi-Fi security protocol by dividing initial authentication and secure session establishment. Once a client is authenticated and equipped with dual tokens issued by AP, it can establish secure session using them quickly with one message exchange over a non-secure channel.

• Journal of Software Assessment and Valuation
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• v.16 no.2
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• pp.143-151
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• 2020

The digital content's security and authentication are important in the field of digital content application. There are some methods to perform the authentication. The digital watermarking is one of authentication methods. Paper presents a digital watermark authentication method that works in the application of digital image. The proposed watermark has the triple status information and performs the embedding and the detection without original Content. When authenticating the owner information of digital content, an autocorrelation function is used. In addition, a spread spectrum method is used to be adaptive to the signal of the original content in the frequency domain(DWT Domain). Therefore, the possibility of errors occurring in the detection of hidden information was reduced. it also has a advantage what Watermarking in DWT has faster embedding and detection time than other transformation domains(DFT, DCT, etc.). if it has a an image of size N=mXm, the computational amount can be reduced from O(N·logN) to O(N). The particular advantage is that it can hide more information(bits) per bit.

• Journal of Advanced Navigation Technology
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• v.13 no.4
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• pp.532-543
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• 2009

As the applications within Internet and Ubiquitous becoming more extensive, the security issues of those applications are appearing to be the most important concern. Therefore, every part of the system should be thoroughly designed and mutually coordinated in order to support overall security of the system. In this paper, we propose new technique which uses the fingerprint features in order to generate Mobile One Time Passwords(OTPs). Fingerprint is considered to be one of the powerful personal authentication factors and it can be used for generating variable passwords for one time use. Also we performed a simulation of homomorphic graph variable of fingerprint feature point using dendrogram and distribution of fingerprint feature points for proposed password generation method.

• Journal of KIISE
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• v.42 no.9
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• pp.1175-1184
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• 2015

Recently, there has been an explosive increase in the volume of multimedia data that is available as a result of the development of multimedia technologies. More and more data is becoming available on a variety of web sites, and it has become increasingly cost prohibitive to have a single data server store and process multimedia files locally. Therefore, many service providers have been likely to outsource data to cloud storage to reduce costs. Such behavior raises one serious concern: how can data users be authenticated in a secure and efficient way? The most widely used password-based authentication methods suffer from numerous disadvantages in terms of security. Multi-factor authentication protocols based on a variety of communication channels, such as SMS, biometric, or hardware tokens, may improve security but inevitably reduce usability. To this end, we present a data block-based authentication scheme that is secure and guarantees usability in such a manner where users do nothing more than enter a password. In addition, the proposed scheme can be effectively used to revoke user rights. To the best of our knowledge, our scheme is the first data block-based authentication scheme for outsourced data that is proven to be secure without degradation in usability. An experiment was conducted using the Amazon EC2 cloud service, and the results show that the proposed scheme guarantees a nearly constant time for user authentication.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.377-380
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• 2002

본 논문에서는 스트림 데이터를 인증하는데 적합한 일회용 서명 기법을 제시한다. 스트림 인증에 일회용 서명 기법을 사용할 경우, 가장 큰 문제점은 큰 서명 크기로 인해 네트워크 오버헤드가 많다는 점이다. 제시한 기법은 기존 일회용 서명 기법 중 서명 크기와 검증 연산량이 가장 낮다. 스트림 인증에 적합한 기존 기법과 서명 연산량을 비교하면, HORS보다는 다소 높지만, BiBa나 Powerball보다 매우 낮다.

• Review of KIISC
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• v.17 no.3
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• pp.26-31
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• 2007

공개된 네트워크 시스템 상에서의 개인 정보를 보호하기 위해 사용자 인증은 시스템 보안에 있어서 중요한 요소이다. 패스워드 기반의 인증 메커니즘은 비용과 효율성의 측면에서 널리 사용되고 있으며 최근 이중요소인증(Two-Factor Authentication)의 한 수단으로 일회용 패스워드(One-Time Password, OTP)를 도입하고 있다. 본고에서는 일회용 패스워드에 대한 인증 기술과 OTP 통합 인증 센터로 구성되는 OTP 통합 인증 시스템에 대해 검토하며 취약성에 대해 살펴보고 이에 대한 대응 방안으로 서비스 제공자의 식별자를 포함한 일회용 패스워드 생성 매체를 이용하는 사용자 인증 시스템을 구성한다. 또한 USB 토큰 형태의 일회용 패스워드 매체를 이용하여 다수의 서비스 제공자의 일회용 패스워드를 지원하는 인증 시스템을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.211-213
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• 2004

무선 인터넷의 활성화와 더불어, 사용자 인증을 위해 801.1x EAP, CHAP 및 PAP를 이용한 다양한 인증 방식이 사용되고 있다. 그 중에서도 RADIUS 및 CiscoSecure ACS와 같은 인증 서버에서는 RSA의 SecureID 및 S/Key와 같은 일회용 패스워드 방식을 지원하고 있다. 본 논문에서는 Casper 도구를 사용하여 CiscoSecure ACS 환경에서 동작하는 일회용 패스워드 방식을 명세하고, 모델체킹 도구인 FDR을 이용하여 안전성을 분석하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.652-654
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• 2003

패스워드를 이용한 사용자 인증은 인증을 요청 한 사용자와 인중 서버간의 인증 자료의 흐름이 매우 중요하다. 사용자 또는 인중 서버의 단 방향에서의 인증이 갖는 한계는 사용자에 대한 비밀 정보를 인중 서버에서 모두 관리함으로써 인증 서버의 해킹에 무방비하다는 점과 단 방향으로의 인증으로 사용자 또는 인증 서버를 가장한 해킹에 취약하다는 단점을 지니고 있다. 그러므로, 본 논문은 사용자-인중 서버를 One Time Password를 이용하여 발생시킨 난수를 기반으로 상호 인중을 할 수 있는 효율적인 방안을 제시하였다.