• Journal of the Korean Chemical Society
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• v.31 no.4
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• pp.352-358
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• 1987

Rate constants for the hydrolysis of para-substituted phenyl N-(p-chlorobenzoyl)chloroformimidate (I) derivatives in 1 : 4 dioxane-water at $25^{\circ}C$ have been determined. Rate data, substituent effect $(\rho\>{\rho}^+)$, product analysis and MO calculation indicate that the uncatalyzed reaction proceeds through an $S_N1$ mechanism involving the formation of azocarbonium ion (II) below pH 3.0, and the base-catalyzed reaction proceeds through an $S_N2$ mechanism via transition state (III) above pH 4.0. The relative stability of four peri planar conformational isomers were (E-ap) > (Z-ap) > (E-sp) > (Z-ap), respectively, and the most stable stereo structures shows that the Y-substituted phenyl group $(C_6H_4-Y)$ occupy vertical $(90^{\circ})$ position on the plane of the benzimidochloroformyl group in (E-ap) conformer. The nucleophilic substitution of water molecule occurs by sigma attack to the activatived azomethine carbon atom of (I) derivatives.

• The KIPS Transactions:PartC
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• v.11C no.2
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• pp.157-162
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• 2004

Recently, the growth of information infrastructure is getting fatter and faster. At the same time, the security accidents are increasing together. We have problem that do not handle traffic because we have the Intrusion Detection Systems in low speed environment. In order to overcome this, we need effective security analysis techniques that ran Processed data of high-capacity because high speed network environment. In this paper we proposed the Gigabit Intrusion Detection System for coordinated security function such as intrusion detection, response on the high speed network. We suggested the detection mechanism in high speed network environment that have pattern matching function based packet header and based packet data that is proceeded in system kernel area, we are shown that this mechanism was excellent until maximum 20 times than existing system in traffic processing performance.

• The KIPS Transactions:PartC
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• v.14C no.2
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• pp.129-138
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• 2007

AAA(Aluthentieation, Authorization, Accounting) protocol is an information securitv technology that offer secure and reliable user Authentication, Authorization, Accounting function systematically in various services. protocol and wireless network work as well as win network. Currently IETF(Internet Engineering Task Force) AAA Working Group deal with about AAA protocol and studying with activity, But, recently it exposing much problems side to user's anonymity and privacv violation. Therefore, in this paper, AAAH(Home Authentication Server) authenticaters Mobile device, after that, use ticket that is issued from AAAH even if move to outside network and can be serviced offering authentication in outside network without approaching by AAAH, Also, we study mechanism that can offer user's privacy and anonymousness to when use service. Our mechanism is using Time Synchronization OTP and focusing authentication and authorization. Therefore, our mechanism is secure from third party attack and offer secure and effective authentication scheme. Also only right user can offer services by using ticket. can reduce signal and reduce delay of message exchanged, can offer persistent service and beighten security and efficiency.

• The KIPS Transactions:PartC
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• v.18C no.2
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• pp.71-78
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• 2011

Financial accidents such as password exposure of credit cards or bankbooks occur often when a password is inputted to ATM/CD(Automated Teller Machines and Cash Dispenser), so particular attention is required when inputting a password. This study suggested a method to input a password safely to prevent stealing a glance at a password in case of the use of ATM/CD. The method is that users input a password when numbers are randomly displayed and disappear not to notice the password even though someone is next to or behind the users. As methods to input a password safely, the study verified safety by dividing the methods into a test of shoulder surfing, an intuitive perspective, and a theoretical analysis. In addition, the result of implementation to apply the method to ATM/CD shows that a percentage of acquiring a password from the attack of shoulder surfing is found to be lower than an existing method, so password exposure can be prevented.

• The KIPS Transactions:PartC
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• v.13C no.2 s.105
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• pp.137-146
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• 2006

Because the traditional public key-based cryptosystems are unsuitable for the sensor node with limited computational and communication capability, a secure communication between two neighbor sensor nodes becomes an important challenging research in sensor network security. Therefore several session key establishment protocols have been proposed for that purpose. In this paper, we analyzed and compared the existing session key establishment protocols based on the criterions of generation strategy and uniqueness of the session key, connectivity, overhead of communication and computation, and vulnerability to attacks. Based on the analysis results, we specify the requirements for the secure and efficient protocols for establishing session keys. Then, we propose an advanced protocol to satisfy the specified requirements and verify the superiority of our protocol over the existing protocols through the detailed analysis.

• The KIPS Transactions:PartC
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• v.9C no.3
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• pp.343-350
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• 2002

This paper describes the implementation of H.235 protocol for authentication and media stream encryption of multimedia conference systems. H.235 protocol is recommended by ITU-T for H.323 multimedia conference security protocol to prevent from being eavesdropped and modified by an illegal attacker. The implementation in this paper has used password-based with symmetric encryption authentication. Media streams are encrypted using the Diffie-Hellman key exchange algorithm and symmetric encryption algorithms such as RC2, DES and Triple-DES. Also, 128-bit Advanced Encryption Standard and 128-bit Korean standard SEED algorithms are implemented for the future extension. The implemented authentication and media stream encryption has shown that it is possible to identify terminal users without exposing personal information on networks and to preserve security of multimedia conference. Also, encryption delay time and used memory are not increased even though supporting media stream encryption/decryption, thus the performance of multimedia conference system has not deteriorated.

• The KIPS Transactions:PartC
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• v.16C no.2
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• pp.189-198
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• 2009

Mobile RFID system is a next generation technology which combines the existing RFID systems with mobile systems. It is newly expected to provide additional services and will be broadly used in everyday life; however, it sometimes causes the privacy or security problems generated by existing RFID systems and the additional privacy or security problems. Moreover, even if many methods have been proposed to solve those problems, it is still difficult to adapt to reality or to guarantee the security perfectly. Therefore, in this paper, we propose the secure and practicable privacy protection mechanism suitable to mobile RFID systems. proposing mechanism is applicable the mechanism to Private Zone of mobile RFID systems which require to protect the privacy. This mechanism suggests that own tagging-products needed to protect privacy using mobile reader of personal don't provide any information to other readers except their own reader. In addition to, proposing mechanism is the efficient mechanism which largely reduces the process to maintain the synchronization when happen to the DoS attack or system error.

• The KIPS Transactions:PartC
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• v.16C no.2
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• pp.199-208
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• 2009

Recently,IP-based broadcasting systems,such as Mobile-TV and IP-TV, have been widely deployed. These systems require a security system to allow only authorized subscribers access to broadcasting services. We analyzed the Conditional Access System, which is a security system used in the IP-based Pay-TV systems. A weakness of the system is that it does not scale well when the system experiences frequent membership changes. In this paper, we propose a group key distribution protocol which overcomes the scalability problem by reducing communication and computation overheads without loss of security strength. Our experimental results show that computation delay of the proposed protocol is smaller than one of the Conditional Access System. This is attributed to the fact that the proposed protocol replaces expensive encryption and decryption with relatively inexpensive arithmetic operations. In addition, the proposed protocol can help to set up a secure channel between a server and a client with the minimum additional overhead.

• The KIPS Transactions:PartC
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• v.16C no.2
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• pp.183-188
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• 2009

Wireless sensor networks will be broadly deployed in the real world and widely utilized for various applications. A prerequisite for secure communication among the sensor nodes is that the nodes should share a session key to bootstrap their trust relationship. The open problems are how to verify the identity of communicating nodes and how to minimize any information about the keys disclosed to the other side during key agreement. At any rate, any one of the existing schemes cannot perfectly solve these problems due to some drawbacks. Accordingly, we propose a new pre-distribution scheme with the following merits. First, it supports authentication services. Second, each node can only find some indices of key spaces that are shared with the other side, without revealing unshared key information. Lastly, it substantially improves resilience of network against node capture. Performance and security analyses have proven that our scheme is suitable for sensor networks in terms of performance and security aspects.

• The KIPS Transactions:PartC
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• v.12C no.2 s.98
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• pp.169-174
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• 2005

Electronic signature system is required to be used in the promotion of the e-Commerce. Because the application system for electronic signature system has inconvenience and vulnerability of security, users are reluctant to use it. Therefore, the electronic signature system should give a guarantee of convenience and security. In this paper, we propose server-based application model, which uses identity information and makes users access transparently to solve electronic signature problems. We also design and verify electronic signature system that reduces threats to security, which cause server attack by distributing the part of signature key to both server and client. The application model with lightweight server system based on the electronic signature system is expected to be used in the promotion of the e-Commerce and help to make its business more efficient and competitive.