• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.20-29
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• 2007

Although E-mail system is considered as a most important communication media, 'Spam' is flooding the Internet with many copies of the same message, in an attempt to force the message on people who would not otherwise choose to receive it. Most spam is commercial advertising, often for dubious products, get-rich-quick schemes, or quasi-legal services. Therefore advanced anti-spam techniques are required to basically reduce its transmission volume on sender mail server or MTA, etc. In this study, we propose a new sender authentication model with encryption function based on modified DomainKey with SMS for Spam mail protection. From the SMS message, we can get secret information used for verification of its real sender on e-mail message. And by distributing this secret information with SMS like out-of-band channel, we can also combine proposed modules with existing PGP scheme for secure e-mail generation and authentication steps. Proposed scheme provide enhanced authentication function and security on Spam mail protection function because it is a 'dual mode' authentication mechanism.

• Review of KIISC
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• v.5 no.4
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• pp.58-90
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• 1995

PGP(Pretty Good Privacy)는 전자우현에 사용되는 보안도구로써 현재 인터넷(Internet)상에서 광범위하게 사용되고 있다. 전자우편에서 필요로 하는 기밀성, 무결성, 송신자 인증, 송신부인방지등의 기능을 모두 제공해 주고 있고 특히, 사용되는 키에 대한 인증을 하나의 기관에서 전담하지 않고, PGP의 사용자들에 의한 키 인증방식을 채택하고 있는 것이 특징이다. 본고에서는 PGP의 효과적인 보급을 위해 전자우편에 필요한 기본 암호 메카니즘과 PGP의 구조 및 사용방법을 살펴본다.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.342-344
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• 1999

인터넷 ED 시스템은 TCP/IP 프로토콜을 사용하여 문서를 전송하게 되는데 전송 도중 패킷 스니핑에 의하여 문서정보가 노출될 수 있다. 이러한 정보노출을 방지 할 수 있는 대표적인 보안 기법에는 인터넷 EDI 보안 프로토콜로 권고되고 있는 S/MIME과 전자우편 암호화 프로그램인 PGP가 있다. S/MIME은 내부에서 사용되는 암호알고리즘의 사용제약으로 인하여 완벽한 구현이 어려우며 PGP의 경우 보안측면에 있어서 수신부인 방지 기능을 제공하지 못하고 있다. 본 논문에서는 S/MIME과 PGP에서 사용되고 있는 보안 기법을 분석하여 기밀성, 인증, 무결성, 송수신 부인방지 기능을 가지는 시스템을 제시한다. 본 시스템은 기존 암호화 알고리즘들의 문제점을 보완할 수 있는 혼합모델을 사용하여 기밀성과 무결성, 송신부인방지 기능을 구현하였고, 인증서버인 삼성 PKI 서버와의 인터페이스를 개발하여 인증을 획득하였다. 수신부인방지의 경우 암호화 메카니즘만으로 획득될 수 없기 때문에 수신자가 문서를 읽는 순간 송신자 측으로 수신자의 전자서명을 자동으로 전송해 주는 프로토콜을 통하여 구현하였다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.6
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• pp.71-80
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• 2002

To provide the confidentiality of messages transmitted over the network, the use of cryptographic system is increasing gradually and the hybrid cryptosystem, which combines the advantages of the symmetric cryptosystem and the public key cryptosystem is widely used. In this paper, we proposes a new hybrid cryptosystem capable of providing implicit authentication for the sender of the ciphertext by means of the 1-pass key distribution protocol that offers implicit key authentication, hash function and symmetric cryptosystem. Also, we describe some examples such as the Diffie-Hellman based system and the Nyberg-Ruppel based system. The proposed hybrid cryptosystem is an efficient more than general public key cryptosystems in the aspect of computation work and provides implicit authentication for the sender without additional increase of the communication overhead.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1293-1296
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• 2010

오늘날 기존의 전력망에 IT가 융합되어 전력 공급자와 송배전 컨트롤러 사이에 정보 교환이 가능한 스마트그리드가 부각되고 있다. 스마트그리드 환경은 전력 공급자와 송배전 컨트롤러 사이의 정보 교환의 빈도가 높고, 정보 교환이 실시간으로 이루어 져야하는 특성을 가진다. 이러한 정보 교환이 주어진 시간 내에 정확하게 이루어지지 않거나 정보 교환 중에 공격자로 인해 악의적 변경이 일어나는 경우 대규모 정전이나 전력의 공급에 막대한 영향을 미치게 된다. 따라서 송신자 인증과 정보 교환 중에 정보의 악의적 변경이 이루어지지 않았다는 정보의 무결성 인증이 이루어 져야 하며, 이를 임계시간 이내에 처리할 수 있는 인증 프로토콜이 요구된다. 본 논문에서는 이러한 요구조건을 만족시키기 위해 타임-크리티컬(time-critical)한 특성을 가지면서 메세지 인증 기능을 제공하는 TV-HORS 멀티캐스트 인증 기법을 스마트그리드 시나리오에 적용하고, 이에 따른 문제점을 제시한 후, 이에 대한 해결책을 제시한다. 제안하는 방법은 키입력(keyed) 해쉬함수를 이용해 기존 TV-HORS 기법이 가지는 키 저장 문제를 효율적으로 해결한다.

• Convergence Security Journal
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• v.2 no.2
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• pp.19-27
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• 2002

This paper proposes a group key management protocol for a secure of all the multicast user in PIM-SM multicast group communication. Each subgroup manager gives a secure key to it's own transmitter and the transmitter compress the data with it's own secure key from the subgroup manager. Before the transmitter send the data to receiver, the transmitter prepares to encrypt a user's service by sending a encryption key to the receiver though the secure channel, after checking the user's validity through the secure channel. As the transmitter sending a data after then, the architecture is designed that the receiver will decode the received data with the transmitter's group key. Therefore, transmission time is shortened because there is no need to data translation by the group key on data sending and the data transmition is possible without new key distribution at path change to shortest path of the router characteristic.

• Convergence Security Journal
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• v.2 no.1
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• pp.99-107
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• 2002

This paper proposes a group key management protocol for a secure of all the multicast user in PIM-SM multicast group communication under electronic commerce. Each subgroup manager gives a secure key to it's own transmitter and the transmitter compress the data with it's own secure key from the subgroup manager. Before the transmitter send the data to receiver, the transmitter prepares to encrypt a user's service by sending a encryption key to the receiver though the secure channel, after checking the user's validity through the secure channel. As the transmitter sending a data after then, the architecture is designed that the receiver will decode the received data with the transmitter's group key. Therefore, transmission time is shortened because there is no need to data translation by the group key on data sending and the data transmition is possible without new key distribution at path change to shortest path of the router characteristic.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.135-142
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• 2010

Wireless mesh network, which is an access network technology, adopts ubiquitous features of ad-hoc network that includes capabilities of self-configuration and self-management. This paper proposes a scheme which enables nodes along route in wireless mesh network to authenticate data and verify data integrity. The scheme distinguishes infra-node, which is a network device used to form mesh network, and user node in ad-hoc network, which operates functions as a sender, receiver or relayer, to deploy different authentication scheme. That is, hop-based authentication scheme along route forming wireless backbone differs from authentication scheme for user nodes in route over MANET. The proposed scheme is less complex than previously proposed schemes from the repects of security setup procedures and managements. In addition, the scheme is able to reduce transmission delay from a source to a destination owing to fast authentication over wireless backbone.

• Journal of Internet Computing and Services
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• v.3 no.5
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• pp.87-94
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• 2002

This paper proposes a group key management protocol for a secure of all the multcast user in PIM-SM multicast group communication. Each subgroup manager gives a secure key to it's own transmitter and the transmitter compress the data with it's own secure key from the subgroup manager, Before the transmitter send the data to receiver, the transmitter prepares to encrypt a user's service by sending a encryption key to the receiver though the secure channel. after checking the user's validity through the secure channel, As the transmitter sending a data after then, the architecture is designed that the receiver will decode the received data with the transmitter's group key, Therefore, transmission time is shortened because there is no need to data translation by the group key on data sending and the data transmition is possible without new key distribution at path change to shortest path of the router characteristic.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.104-110
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• 2003

In this paper, we proposed hybrid cryptosystem of Diffie-Hellman base in Elliptic Curve, and explained for specific protocol design. The proposed system is efficient hybrid cryptosystems system that offer implicit key authentication about sender and receiver unlike existing hybrid system. This system increased safety generating session key using pseudo-random number generator by cryptographic. Because the system is hybrid system, it is more efficient in calculation amount aspect supplementing merit and fault of public key system and secret key system. Also, the system can not get right plaintext except receiver even if sender's secret key is revealed and impersonation attack is impossible. And the system offers security on known keys without influencing in safety of other session's cryptogram even if session key is exposed. And the system is provided safety about mutual entity authentication and replay attack.