• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.5
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• pp.103-113
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• 2008

Reducing handoff latency is essential in providing seamless multimedia service in Wireless LAN based on the IEEE 802.11 standard. Reducing authentication delay is critical in reducing handoff latency. To this end, several authentication protocols for fBst handoff have been proposed. Mishra et al. used proactive key distribution to improve the authentication delay incurred in the current standard and Park et al. proposed a new authentication protocol based on Blom's key pre-distribution scheme. In this paper, we propose an enhanced authentication protocol based on Bresson et al.'s group key protocol. If a mobile node has previously access the network, our proposed protocol only requires simple hash operations in providing mutual authentication between a mobile node and access points. Our protocol is more efficient than Park et al.'s and Mishra et al.'s technique can be used in our protocol to further enhance our protocol.

• Journal of Communications and Networks
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• v.10 no.1
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• pp.18-27
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• 2008

This paper is to study a subclass of group-oriented cryptographic scheme: Many-to-one encryption and authentication scheme. The many-to-one encryption and authentication scheme is to solve a practical problem, i.e., the scenario that the number of the receivers is very small compared with the number of the senders and a receiver may serve millions of senders. Compared with the traditional methods, the burdens of the receiver and the KGC are reduced greatly. How to revoke a sender from his receiver's legitimate sender group is also proposed and it is efficient compared with some traditional methods. The proposed scheme is proven in the random oracle models. The computational complexity of our scheme is independent of the number of the senders. At the end of the paper, an example is given to show how to use our scheme in online software registration and update.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.765-772
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• 2004

Multicast communication is simultaneous transmission of data to multiple receivers and saves considerably sender resources and network bandwidth. It has high risk to attack using group address and inherent complexity of routing packets to a large group of receivers. It is therefore critical to provide source authentication, allowing a receiver to ensure that received data is authentic. In this paper, we propose the multiple chain authentication scheme for secure and efficient multicast stream. To evaluate the performance of our scheme, we compare our technique with two other previously proposed schemes using simulation results. Our scheme provides non-repudiation of origin, low overhead by amortizing the signature operation over multiple packets, and high packet loss resistance.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.3
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• pp.53-64
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• 2005

In this paper, proposes Kerberos certification mechanism that improve certification service of PKINIT base that announce in IETF CAT Working Croup. Also proposed Authentication Mechanism for reusability of Ticket that after Ticket's Lifetime is ended, message exchange that Local Client receives Remote Server's service. Since my suggestion to regional services are not described in Kerberos, authentication between regions can be performed via PKINIT(Public Key Cryptography for Initial Authentication) presented by IETF(Internet Engineering Task Force) CAT working group. The new protocol is better than the authentication mechanism proposed by IETF CAT Working group in terms of communication complexity and mechanism according to simplified Ticket issue processing.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.2
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• pp.239-248
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• 2012

VANET (Vehicular Ad-hoc Network) is a type of MANET (Mobile Ad-hoc Network) which is the next-generation networking technology to provide communication between vehicles or between vehicle and RSU (Road Side Unit) using wireless communication. In VANET system, a vehicle accident is likely to cause awful disaster. Therefore, in VANET environment, authentication techniques for the privacy protection and message are needed. In order to provide them privacy, authentication, and conditional, non-repudiation features of the group signature scheme using a variety of security technologies are being studied. In this paper, and withdrawal of group members to avoid frequent VANET environment is suitable for vehicles produced by the group administrator for a private signing key to solve the key escrow problem of a group signature scheme is proposed. We proposed a message batch verification scheme using Bloom Filter that can verify multiple messages efficiently even for multiple communications with many vehicles.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.1
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• pp.67-80
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• 2007

Nateon Messenger, which has the most number of users in Korea, supports many services such as E-mail, note, Cyworld, SMS, etc. In this paper, we will analyse the authentication traffic which is transmitted and received by the Nateon Messenger. Through performing the replay attack with the authentication information, we will show that an attacker can be authenticated illegally. Furthermore, we will show that other domestic messengers have similar security problems.

• The Korea Journal of Herbology
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• v.28 no.6
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• pp.53-58
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• 2013

Objectives : Pinelliae Tuber has been used as a typical unauthentic herbal medicines. Due to the morphological similarity between Pinelliae Tuber and adulterants, the correct authentication is very difficult. Therefore, we introduced DNA barcode to establish a powerful tool for the authentication of Pinelliae Tuner from adulterants. Methods : To obtain DNA barcode regions, genomic DNA was extracted from nineteen specimens of Pinellia ternata, Pinellia pedatisecta, Pinellia tripartita, and Typhonium flagelliforme, and matK and rbcL genes were amplified. For identification of species specific sequences and analysis phylogenetic relationship, a comparative analysis were performed by the ClastalW and UPGMA based on entire sequences of matK and rbcL genes, respectively. Results : In comparison of two DNA barcode sequences, we elucidated the phylogenetic relationship showing distinct four groups depending on species and identified 40 and 20 species specific nucleotides enough to distinguish each species from matK and rbcL gene, respectively. The sequence differences at the corresponding positions were avaliable genetic marker nulceotides to discriminate the correct species among analyzed four species. These results indicated that phylogentic and comparative analysis of matK and rbcL genes are useful genetic markers to authenticate Pinelliae Tubers. Conclusions : The marker nucleotides enough to distinguish P. ternata, P. tripatrita, P. peditisecta, and T. flagelliform, were observed at 40 positions in matK gene and 20 positions in rbcL gene sequence, respectively. These differences can be used to authenticate Pinelliae Tuber from adulterants as well as discriminate each four species.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.641-647
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• 2023

In the fintech environment, ensuring secure financial transactions with smartphones requires authenticating the device owner. Smartphone authentication techniques encompass a variety of approaches, such as passwords, biometrics, SMS authentication, and more. Among these, password-based authentication is commonly used and highly convenient for user authentication. Although it is a simple authentication mechanism, it is susceptible to eavesdropping and keylogging attacks, alongside other threats. Security keypads have been proposed to address vulnerabilities in password input on smartphones. One such innovation is a group keypad, resistant to attacks that guess characters based on touch location. However, improvements are needed for user convenience. In this study, we aim to propose a method that enhances convenience while being resistant to eavesdropping and recording attacks on the existing group keypad. The proposed method uses new signs to allow users to verify instead of the last character confirmation easily and employs dragging-to-touch for blocking recording attacks. We suggest diverse positioning methods tailored for domestic users, improving efficiency and security in password input compared to existing methods.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.10
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• pp.40-48
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• 2008

Security of self organized mobile ad hoc networks is an important issue because administration information in the networks is managed by the constituent nodes. Especially authentication mechanism is necessary for trust setup between newly joining nodes and the network. The authentication models and protocols which are based on the wireline infrastructure could not be practical for mobile ad hoc network. Although public key algorithm-based method is widely used for authentication, it is not easy to be applied to mobile ad hoc networks because they do not have infrastructure such as centralized CA which is needed for certificate verification. In this paper, we consider the public key based random CA group method proposed in [1] to provide efficient authentication scheme to mobile ad hoc networks and analyze the performance of the method, which is then compared to the home CA method. From the analysis results, we see that the random CA method where the function of CA is distributed to some mobile nodes and the authentication information is propagated to randomly chosen CAs shows higher reliability and lower cost than home CA method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.3
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• pp.1144-1156
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• 2014

In Internet, IP multicast has been used successfully to provide an efficient, best-effort delivery service for group communication applications. However, applications such as multiparty private conference, distribution of stock market information, pay per view and other subscriber services may require secure multicast to protect integrity and confidentiality of the group traffic, and validate message authenticity. Providing secure multicast for group communication is problematic without a robust group key management. In this paper, we propose a group key management scheme based on the secret sharing technology to require each member by itself to generate the group key when receiving a rekeying message multicast by the group key distributor. The proposed scheme enforces mutual authentication between a member and the group key distributor while executing the rekeying process, and provides forward secrecy and backward secrecy properties, and resists replay attack, impersonating attack, group key disclosing attack and malicious insider attack.