• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.17-30
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• 2008

In the paper, we consider password-based authenticated key exchange with different passwords, where the users do not share a password between themselves, but only with the server. The users make a session key using their different passwords with the help of the server. We propose an efficient password-based authenticated key exchange protocol with different passwords which achieves forward secrecy without random oracles. In fact this amount of computation and the number of rounds are comparable to the most efficient password-based authenticated key exchange protocol in the random oracle model. The protocol requires a client only to memorize a human-memorable password, and all other information necessary to run the protocol is made public.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.5
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• pp.827-835
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• 2022

In order to use online financial services, user authentication technology is necessary. Password check through keyboard typing is the most common technique. However, since it became known that key stokes on the keyboard can be intercepted easily, many Internet banking services and easy payment services have adopted the virtual keyboard. However, contrary to the expectation that the virtual keyboard will be safe, there is a risk that key strokes on the virtual keyboard can be leaked. In this paper, we analyzed the possibility of password leaking on the virtual keyboard and presented a password leaking method using mouse event hooking and screen capture in PC operating system. In addition, we inspected the possibility of password leak attacks on several famous Korea Internet banking websites and simple payment services, and as a result, we verified that the password input method through the virtual keyboard in the PC operating system is not secure.

• Journal of Industrial Convergence
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• v.21 no.9
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• pp.49-56
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• 2023

ID is used as identifying information and password as user authentication for ID-based authentication. In order to have a secure user authentication, the password is generated as a hash value on the client and sent to the server, where it is compared with the stored information and authentication is performed. However, if even one character is incorrect, the different hash value is generated, authentication will be failed and cannot be performed and various functions cannot be applied to the password. In this study, we generate several hash value including imaginary number of entered password and transmit to server and perform authentcation. we propose a technique can grants the right differentially to give various rights to the user who have many rights by one account. This can defend shoulder surfing attack by imaginary password and provide convenience to users who have various rights by granting right based on password.

• Journal of KIISE:Information Networking
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• v.30 no.1
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• pp.75-81
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• 2003

User authentication, including confidentiality, integrity over untrusted networks, is an important part of security for systems that allow remote access. Using human-memorable Password for remote user authentication is not easy due to the low entropy of the password, which constrained by the memory of the user. This paper presents a new password authentication and key agreement protocol suitable for authenticating users and exchanging keys over an insecure channel. The new protocol resists the dictionary attack and offers perfect forward secrecy, which means that revealing the password to an attacher does not help him obtain the session keys of past sessions against future compromises. Additionally user passwords are stored in a form that is not plaintext-equivalent to the password itself, so an attacker who captures the password database cannot use it directly to compromise security and gain immediate access to the server. It does not have to resort to a PKI or trusted third party such as a key server or arbitrator So no keys and certificates stored on the users computer. Further desirable properties are to minimize setup time by keeping the number of flows and the computation time. This is very useful in application which secure password authentication is required such as home banking through web, SSL, SET, IPSEC, telnet, ftp, and user mobile situation.

• Journal of Advanced Navigation Technology
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• v.14 no.3
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• pp.415-425
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• 2010

In public network, user authentication is important security technology. Especially, password-based authentication method is used the most widely in distributed environments, and there are many authentication methods. Their SPMA protocol indicates vulnerability about problem that NSPA protocol does not offer mutual authentication, and proposed Strong Password Mutual Authentication protocol with mutual authentication. However, SPMA protocol has vulnerability of replay attack. In the paper, we analyzed vulnerability to replay attack of SPMA protocol. And we also proposed Improved Strong Password Mutual Authentication protocol to secure on replay attack with same efficiency.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.195-200
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• 2012

Smart Phone devices offer convenience for users, but present a new set of security issues due to loss or malicious code. In this paper, a mobile cloud system environment is used with existing smart phones in an attempt to solve the problems in a banking environment. In order to prevent financial damages due to loss or personal information leakage by malicious code, a mobile cloud computing service that provides control and protection of personal information in environment that ensures individual authentication is used. Existing ID / Password with certificate, with the way smart phone dual password authentication scheme using the gyro sensors proposed.

• 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.12
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• pp.4987-5014
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• 2015

The bilinear pairing, also known as Weil pairing or Tate pairing, is widely used in cryptography and its properties help to construct cryptographic schemes for different applications in which the security of the transmitted data is a major concern. In remote login authentication schemes, there are two major requirements: i) proving the identity of a user and the server for legitimacy without exposing their private keys and ii) freedom for a user to choose and change his password (private key) efficiently. Most of the existing methods based on the bilinear property have some security breaches due to the lack of features and the design issues. In this paper, we develop a new scheme using the bilinear property of an elliptic point and the biometric characteristics. Our method provides many features along with three major goals. a) Checking the correctness of the password before sending the authentication message, which prevents the wastage of communication cost; b) Efficient password change phase in which the user is asked to give a new password after checking the correctness of the current password without involving the server; c) User anonymity - enforcing the suitability of our scheme for applications in which a user does not want to disclose his identity. We use BAN logic to ensure the mutual authentication and session key agreement properties. The paper provides informal security analysis to illustrate that our scheme resists all the security attacks. Furthermore, we use the AVISPA tool for formal security verification of our scheme.

• Journal of KIISE:Information Networking
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• v.31 no.3
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• pp.252-258
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• 2004

In this paper, we propose a new authenticated key exchange protocol in which client and sever can mutually authenticate and establish a session key over an insecure channel using only a human memorable password. The proposed protocol is based on Diffie-Hellman scheme and has many of desirable security attributes: It resists off-line dictionary attacks mounted by either Passive or active adversaries over network, allowing low-entropy Passwords to be used safely. It also offers perfect forward secrecy, which protects past sessions when passwords are compromised. In particular, the advantage of our scheme is that it is secure against an impersonation attack, even if a server's password file is exposed to an adversary. The proposed scheme here shows that it has better performance when compared to the previous notable password-based key exchange methods.

• The KIPS Transactions:PartD
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• v.14D no.4 s.114
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• pp.363-372
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• 2007

Password, a traditional user confirmation method that is used for more than 100 years, has become useless as a lot of transactions are dealt by indirect contacts. As a result, an alternative for password is required now. In this paper, we propose a novel confirmation method, which is called Brain-Key. It uses an indirect password input method. It reduces the risks due to hacking, and prevents a big credit accident because it prevents passwords to be reused. Our proposed model has general applicability so that it can be applied in domestic market as well as international markets. This research may provide solutions for the security problems in the electronic commerce.