• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.375-378
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• 2001

엔터프라이즈 환경에서 데이터의 교환을 위해 메시지중계시스템을 사용하고 있다. 그러나, 현재 사용하고 있는 메시지중계시스템 자체에는 정보보호서비스가 적용된 예가 많지 않으며 일부 적용된 경우에도 접근제어 서비스를 제공하고 있지 못하다. 본 논문에서 제안하는 PMI(Privilege Management Infrastructure)기반의 메시지중계시스템은 기존의 구축되어 있는 PKI(Public Key Infrastructure)를 이용하여 정보보호서비스의 인증, 무결성, 기밀성, 부인방지 서비스를 제공하며 PMI을 적용하여 접근제어 서비스를 제공한다. PMI의 속성인증서를 사용하여 실시간적으로 변하는 접근제어 정보의 변화를 수용하며 SOA(Sorce of Authority)를 통해 중앙에서 접근제어정보를 관리한다. 교환되는 데이터는 S/MIME을 기본으로 하여 국제표준을 따르며 S/MIME의 보안 레이블을 이용 데이터의 변경없이 접근제어 정보를 전송할 수 있도록 하였다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.2
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• pp.13-29
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• 2003

Web-mail system is worthy of note as a next generation e-mail system for its mobility and easiness. But many web-mail system does not have any kind of security mechanism. Even if web-mail system provides security services, its degree of strength is too low. Using these web-mail systems, the e-mail is tabbed, modified or forged by attacker easily. To solve these problems, we design and implement secure web-mail system based on the international e-mail security standard S/MIME in this thesis. This secure web-mail system is composed of server system and client system The server system performs basic mail functions - sending/receiving the mails, storing the mails, and management of user information, etc. And the client system performs cryptographic functions - encryption/decryption of the mails, digital signing and validation, etc. Because client system performs cryptographic functions this secure web-mail system gives its reliability and safety, and provides end-to-end security between mail users. Also, this secure web-mail system increase system efficiency by minimize server load.

• (The) Research of the performance art and culture
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• no.18
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• pp.47-72
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• 2009

This study explores mime elements of court Hagmu(鶴舞) in literature and what is expressed in the practice of current Hagmu and examines what has been changed while others are kept intact. The content of Hagmu is that "attracted by lotus flowers in a pond, cranes dance around and peck at them, when the blossoms open wide with a girl [dancer] inside, upon which the surprised cranes fly away." The dance consists of 4 steps: the first step is for the entrance of cranes; in the second step the cranes dance moving across jidang(池塘) and the north; in the third step the cranes are curious about the lotus calyces, yeontong(蓮筒); and the cranes withdraw in the fourth step. The literature suggests that the dancing courses on the stage are limited to the east, the west, the south, and the north. The movement is limited to naeson (內旋) only in mujin(舞進) and mutoe(舞退). Furthermore, the gaze is only allowed toward the north and jidang. Motions are limited to naejog(內足), oego (外顧), and naego(內顧). However, the mime elements of current Hagmu are attributed to the effort of translating crane's life into a realistic story. It relates the life of cranes to that of human beings and implies love in it. Finally, the court Hagmu has entered the real world out of the literature, enriched with new elements. Under the transition from literature to practice the diversity of expression is added while the elements related with court codes such as courses, movements, directions, and motions are kept intact. These limitations, however, are coupled with the sensitive 'love' and the exposure of dancing instruments intrigues audience and creates dramatic effect. In conclusion the significance of mime elements in court Hagmu is in enhancing communication with audience.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.4
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• pp.99-106
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• 2017

With the advent of virtual money such as bit coins, interest in the block chain is increasing. Block Chain is a technology that supports Distributed Ledger and is a versatile technology applicable to various fields. Currently, the block chain is conducting research for various applications such as virtual money, trade finance, marketplace, power market, image contents service, and IoT. The technologies that make up the block chain are smart contract, digital signature/hash function and consensus algorithm. And these technologies operate on P2P networks. In this paper, we have studied e-mail system based on the ethereum which is one of the block chain based technologies. Most legacy mail systems use SMTP and the POP3/IMAP protocol to send and receive e-mail, and e-mail use S/MIME to protect the e-mail. However, S/MIME is vulnerable to DDoS attacks because it is configured centrally. And it also does not provide non-repudiation of mail reception. To overcome these weaknesses, we proposed an e-mail system model based on ethereum. The proposed model is able to cope with DDoS attack and forgery prevention by using block chain based technology, and reliable recording and management among block chain participants are provided, so that it is possible to provide a non-repudiation function of e-mail transmission and reception.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.313-317
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• 2001

본 논문에서는 전자메일에 보안기능과 공중기능을 함께 부여하는 방법에 대해 기술하고 있다. MIME(Multipurpose Internet Mail Extensions)[8]에 대하여 메시지의 무결성과 전자서명 생성 및 검증, 메시지의 암호화 및 복호화, 부인방지 기능을 지원하기 위해S/MIME(Secure/Multipurpose Internet Mail Extensions)[1][2]을 적용하고 또한 문서에 대한 공증기능을 부여하기 위하여 서명 생성 후 오랜 기간 뒤에도 서명과 서명 생성 시 사용된 인증서의 유효성과 폐지여부를 검증 할 수 있도록 제 3 신뢰기관에 의해 발행된 Timestamp[7]를 적용하였다. 그리고 서명된 메일 형식에 receiptRequest[4] 식별자를 사용하여 수신자의 서명을 포함한 signed receipt[4]를 송신자에게 다시 보내게 하여 메일 수신여부를 검증 할 수 있도록 하였다.

• (The) Research of the performance art and culture
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• no.18
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• pp.137-169
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• 2009

This paper pay attention to silent puppets which appear in the traditional puppet performance. Not only movement of silent puppets which are involved with expression of body of the mime, but also various methods overcome limits of the silent are studied in this paper. Through the study of performance method and historic unfolding aspects, I confirm two main points. First point is that overcome limits of the silent, through the diversity of performance aspects. Second point is that silent puppets have been existed since the early stage of history, and show typical unfolding aspects on their way. Combining two main points, We can say that silent puppets go through continuous unfolding aspects on their way and have meaning of existence. The meaning of existence are that silent puppets seek deviant desire which deviate from everyday life and transcendental desire which seek a freedom through an imagination or an idea. It is interesting that the reasons of existence are associated with the emphasis of necessity which is encouragement of audience's desire and imagination that are necessary of accomplish of mime. After all, silent puppets say that diverse attempts which overcome limits of the silent are accomplished with the performance aspects and historic unfolding aspects, and through that sought unusual communication. Through the performance methods and signification aspects, silent puppets say that diverse groping for which maximize of audience's imagination, stimulation of imagination for audience's spontaneousness, and diverse groping for audience mind performance have been performanced as well. I think that those are the voice of silent puppets for activity of mime in the korea.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.563-572
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• 1997

E-mail has been eidely used for unformation delivery as an Inernet serive. As multimedia etchnologies are developed rapidly, most of the recent Unternet infornation servies support multimedia data. E-mail system also needs to suport multimedia nesage. But Internet mail servise using simple maiol transfer protocol(SMTP) speci-fied in RFC 821/822 handles only ASCII text messages repressented with 7-bit code. Each line the message has the length limitation as well. Those are why it cannot satisfy the diverse user'w demands. Multipuepose Unternet mail extensions(MIMZE), which is a modification and supplement of RFC 822,was proposed for supporting transportation of multimedia data.It can solve the limitations of sizes and types in contents of a message. In this study the E-mail system has been designed and implemented according to the MIME standard in order to solve the limitations of transpotation of messages regardless of the message content type. Hypertext markup language(HTML)syntax is applied to the mail system, and so it is possible to display a message consisting of differnt media as an intergrated from for the purpose of better understanding a message. No application program is needed for displaying a message including image data,and convenience for user is considered in the system. The futuer work is to improve the E-mail system so that it may support motion pictures and sound information,Thereby tge perfor multimeda E-mail system providing inergrated user's wiew will be developed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12B
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• pp.750-757
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• 2007

This paper analyzes spam threats and proposes key exchange scheme for user authentication and SDP encryption to protect potential spam threats in SIP-based VoIP services. The existing HTTP digest authentication scheme exchanges many message because challenge is sent for every establishment of the session and doesn't provide a confidentiality of SDP. To protect SPIT, our scheme exchanges initial nonce and a session master key for authentication and SDP encryption during registration. In our scheme, the challenge and response procedure is not necessary and the communication overhead is much less than applying S/MIME or TLS.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.435-440
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• 2006

XML encryption is to provide confidentiality service, though not limited to, for web contents. XML encryption can be applied to entire data files as opaque objects, or more frequently to various parts of XML documents, supporting various encryption granularity. It is this characteristic that makes XML encryption a more efficient alternative for data confidentiality in various web applications than is possible with SSL/TLS, IPsec, PGP, or S/MIME. It is essential for successful deployment of XML encryption to achieve interoperability among the products implementing this technology, which requires the products to implement the XML encryption standards correctly. Conformance testing is to test if products implement the relevant standard correctly. In this paper we present a conformance testing method for XML encryption products and implement it. We will first look at XML encryption standards developed by W3C, and extract test criteria. Then we propose a testing method in which the encryption capability and the decryption capability of a product are tested separately. The proposed methody is actually implemented as a GUI-based testing tool and some test results are presented.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.5
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• pp.27-38
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• 2007

One of the most important security issues of e-mail service is user privacy. Currently, various security protocols, like PGP(pretty Good Privacy), S/MIME(Secure/Multipurpose Internet Mail Extension), have been proposed. These protocols, however, do not provide forward secrecy. Recently, some security protocols that provide forward secrecy were proposed. But all of them require changes to the current e-mail infrastructure. Moreover, contrary to authors' intention, some of them do not actually provide perfect forward secrecy. In this paper, we propose a new practical e-mail security protocol. The proposed protocol provides perfect forward secrecy and uses a practical e-mail model that dose not require any changes to existing e-mail servers. It encrypts and authenticates messages efficiently using elliptic curve based signcryption scheme. In addition, we provide a way to send secure group e-mails.