• Journal of KIISE:Computer Systems and Theory
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• v.36 no.4
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• pp.304-310
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• 2009

Due to widely use of internet, a lot of users frequently access into remote server in distributed computing environment. However, transmitting the information using vulnerable channel without authentication security system can be exposed to replay attack, offline password attack, and impersonation attack. According to this possibility, there is research about authentication protocol to prevent these hostile attacks using smart card. In this paper, we analyze vulnerability of user authentication system based on password and propose modified user authentication system.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.35-43
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• 2017

In 2013, Lee-Lie proposed secure smart card based authentication scheme of Zhu's authentication for TMIS which is secure against the various attacks and efficient password change. In this paper, we discuss the security of Lee-Lie's smart card-based authentication scheme, and we have shown that Lee-Lie's authentication scheme is still insecure against the various attacks. Also, we proposed the improved scheme to overcome these security problems of Lee-Lie's authentication scheme, even if the secret information stored in the smart card is revealed. As a result, we can see that the improved smart card based user authentication scheme for TMIS is secure against the insider attack, the password guessing attack, the user impersonation attack, the server masquerading attack, the session key generation attack and provides mutual authentication between the user and the telecare system.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.2
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• pp.27-33
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• 2018

User authentication scheme is a method for controlling unauthorized users' access to securely share the services and resources provided by the server and for verifying users with access rights. Initial user authentication scheme was based on passwords. Nowadays, various authentication schemes such as ID based, smart-card based, and attribute based are being researched. The study of Lee et al. suggested a user authentication scheme that provides forward secrecy and protects anonymity of users. However, it is vulnerable to attacks by outsiders and attackers who have acquired smart-cards. In this paper, we propose a modified smart-card authentication scheme to complement the weakness of the previous studies. The proposed user authentication scheme provides the security for the ID guessing attack and the password guessing attacks of the attacker who obtained the login request message and the user's smart-card.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.713-716
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• 2007

This paper suggests One-time Password key exchange authentication technique for a strong authentication based on Ad-hoc Networks and through identify wireless environment security vulnerabilities, analyzes current authentication techniques. The suggested authentication technique consists of 3 steps: Routing, Registration, and Running. The Routing step sets a safe route using AODV protocol. The Registration and Running step apply the One-time password S/key and the DH-EKE based on the password, for source node authentication. In setting the Session key for safe packet transmission and data encryption, the suggested authentication technique encrypts message as H(pwd) verifiers, performs key exchange and utilizes One time password for the password possession verification and the efficiency enhancement. EKE sets end to end session key using the DH-EKE in which it expounds the identifier to hash function with the modula exponent. A safe session key exchange is possible through encryption of the H(pwd) verifier.

• Journal of Advanced Information Technology and Convergence
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• v.8 no.2
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• pp.41-46
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• 2018

As evidenced through rapidly growing digital devices and information, digital authentication is becoming ever more critical, especially considering the complex and prevalent digital accounts we are using every day. Also, digital authentication is apt to consistent digital security application. In this sense, digital security quality and usability can be enhanced by developing a mechanism for efficient digital authentication. In this paper, a mechanism of efficient digital authentication called T-TIME is introduced in order to alleviate issues dealing with secure and user friendly authentication across ever- growing digital devices and information. Touch Signal generation time difference is utilized for T-TIME as a mediation mechanism that enhances the security quality by confusing others unlike other graphical password mechanisms which are using spatial information. Hence, digital authentication by using T-TIME can be a good way of enhancing security quality and usability.

• Journal of information and communication convergence engineering
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• v.4 no.4
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• pp.166-169
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• 2006

Almost all network systems provide an authentication mechanism based on user ID and password. In such system, it is easy to obtain the user password using a sniffer program with illegal eavesdropping. The one-time password and challenge-response method are useful authentication schemes that protect the user passwords against eavesdropping. In client/server environments, the one-time password scheme using time is especially useful because it solves the synchronization problem. In this paper, we present a new identification scheme: OPI(One Pass Identification). The security of OPI is based on the square root problem, and OPI is secure: against the well known attacks including pre-play attack, off-line dictionary attack and server comprise. A number of pass of OPI is one, and OPI processes the password and does not need the key. We think that OPI is excellent for the consuming time to verify the prover.

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.722-732
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• 2016

A new optical one-time password (OTP) authentication method using digital holography is proposed, which enhances security strength in the authentication system. A challenge-response optical OTP algorithm based on two-factor authentication is presented using two-step phase-shifting digital holography, and two-way authentication is also performed using challenge-response handshake in both directions. Identification (ID), password (PW), and OTP are encrypted with a shared key by applying phase-shifting digital holography, and these encrypted pieces of information are verified by each party by means of the shared key. The encrypted digital holograms are obtained by Fourier-transform holography and are recorded on a CCD with 256 quantized gray-level intensities. Because the intensity pattern of such an encrypted digital hologram is distributed randomly, it guards against a replay attack and results in higher security level. The proposed method has advantages, in that it does not require a time-synchronized OTP, and can be applied to various authentication applications. Computer experiments show that the proposed method is feasible for high-security OTP authentication.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.3
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• pp.69-77
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• 2010

Authentication and key establishment are fundamental procedures to establish secure communications over public insecure network. A password-based scheme is common method to provide authentication. In 2008, Khan proposed an efficient password-based authentication scheme using smart cards to solve the problems inherent in Wu-Chieu's authentication scheme. As for security, Khan claimed that his scheme is secure and provides mutual authentication between legal users and a remote server. In this paper, we demonstrate Khan's scheme to be vulnerable to various attacks, i. e., password guessing attack, insider attack, reflection attack and forgery attack. Our study shows that Khan's scheme does not provide mutual authentication and is insecure for practical applications. This paper proposes an improved scheme to overcome these problems and to preserve user anonymity that is an issue in e-commerce applications.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.3
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• pp.182-188
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• 2011

Recently Yoon et al. proposed the remote user authentication scheme using smart cards. But their scheme has not satisfied security requirements which should be considered in the user authentication scheme using the password based smart card. In this paper, we prove that Yoon et al.'s scheme is vulnerable to a password guessing attack in case that the attacker steals the user's smart card and extracts the information from the smart card. Accordingly, this paper proposes the improved user authentication scheme based on the hash functin and random nonce that can withstand various possible attacks including a password guessing attack. The result of comparative analysis demonstrates that the proposed scheme is more secure and efficient than Yoon et al.'s scheme, with a trivial trade-off to require just a few more exclusive-OR operations.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.173-181
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• 2011

User authentication and key exchange protocols are the most important cryptographic applications. For user authentication, most protocols are based on the users' secret passwords. However, protocols based on the users' secret passwords are vulnerable to the password guessing attack. In 1992, Bellovin and Merritt proposed an EKE(Encrypted Key Exchange) protocol for user authentication and key exchage that is secure against password guessing attack. After that, many enhanced and secure EKE protocols are proposed so far. In 2006, Lo pointed out that Yeh et al.'s password-based authenticated key exchange protocol has a security weakness and proposed an improved protocol. However, Cao and Lin showed that his protocol is also vulnerable to off-line password guessing attack. In this paper, we show his protocol is vulnerable to on-line password guessing attack using new attack method, and propose an improvement of password authenticated key exchange protocol for imbalanced wireless networks secure against password guessing attack.