• Journal of KIISE:Software and Applications
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• v.31 no.8
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• pp.1092-1100
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• 2004

An E-mails have regarded as one of the most popular methods for exchanging information because of easy usage and low cost. Meanwhile, exponentially growing unwanted mails in user's mailbox have been raised as main problem. Recognizing this issue, Korean government established a law in order to prevent e-mail abuse. In this paper we suggest hybrid spam mail filtering system using weighted Bayesian classifier which is extended from naive Bayesian classifier by adding the concept of preprocessing and intelligent agents. This system can classify spam mails automatically by using training data without manual definition of message rules. Particularly, we improved filtering efficiency by imposing weight on some character by feature extraction from spam mails. Finally, we show efficiency comparison among four cases - naive Bayesian, weighting on e-mail header, weighting on HTML tags, weighting on hyperlinks and combining all of four cases. As compared with naive Bayesian classifier, the proposed system obtained 5.7% decreased precision, while the recall and F-measure of this system increased by 33.3% and 31.2%, respectively.

• Journal of Intelligence and Information Systems
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• v.10 no.2
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• pp.79-89
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• 2004

Since the amount of E-mail messages has increased , we need a new technique for efficient e-mail classification. E-mail classifications are grouped into two classes: binary classification, multi-classification. The current binary classification methods are mostly spm mail classification methods which are based on rule driven, bayesian, SVM, etc. The current multi- classification methods are based on clustering which groups e-mails by similarity. In this paper, we propose a novel method for e-mail classification. It combines the automatic category generation method based on the vector model and the dynamic category hierarchy construction method. This method can multi-classify e-mail automatically and manage a large amount of e-mail efficiently. In addition, this method increases the search accuracy by dynamic reclassification of e-mails.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.337-341
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• 2006

Spam email is an electronic mail sent to a large number of netizen who do not want it. Criminals have been to take an advantage of this tool easily through harmful activities such as phishing. Recently the spam mail containing commercial information is broadly accepted as an illegal commitment to endangering the network. According some report, it could cause real damages. For the better policy on controlling spam mail we need new Efficient Countermeasure. Several laws have been enacted in Korea for controlling spam mail. The most important acts is the Using and Protecting Communication Act. Main targets of this law is virus spreading, computer hacking, cyber pornography, intellectual property breaching, private or public information abusing and cyber terrorism. But the Using and Protecting Communication Act is insufficient to control spam mail. For the better policy on controlling spam mail we need new Efficient Countermeasure. Therefore, this research wishes to present way to control for efficient spam mail through enactment of conversion, induction of clash action system degree, special law of national regulation form for spam mail.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.1
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• pp.3-11
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• 2009

Forward secrecy in an e-mail system means that the compromising of the long-term secret keys of the mail users and mail servers does not affect the confidentiality of the previous e-mail messages. Previous forward-secure e-mail protocols used the certified public keys of the users and thus needed PKI(Public Key Infrastructure). In this paper, we propose a password-based authenticated e-mail protocol providing forward secrecy. The proposed protocol does not require certified public keys and is sufficiently efficient to be executed on resource-restricted mobile devices.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11a
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• pp.166-169
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• 2003

본 논문에서는 비밀분산기법과 임계 암호시스템을 사용하여 사용자의 공개키 암호 알고리즘 연산과 공개키 유효성 검증에 대한 연산의 오버헤드를 최소화시킨 새로운 Certified E-mail 시스템을 제안한다. 따라서, 제안 방안은 셀룰러 폰이나 무선 PDA와 같은 컴퓨팅 파워가 취약한 메일 사용자에게 적합하다 또한, 제안 시스템은 신뢰성을 완전히 분산시킨 TTP(Trusted Third Party)를 사용함으로써, TTP의 훼손이나 악의적인 사용자의 공모 공격에 강건하도록 설계되었다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.307-309
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• 2002

정보의 다양화와 급속한 정보량의 증가로 정보검색 시스템의 필요성이 증대되고 있다. 그러나 현재 시스템 자체로는 사용자들의 요구나 선호도를 만족시킬 수 없고 그만큼 사용자에게 편의성을 제공하지 못한다. E-mail의 정보를 보다 효율적으로 관리하기 위하여 사용자가 원하는 문서를 그룹핑하고 지식라인 생성이 가능한 문서 관리기 시스템을 생성해야한다. 따라서 본 논문에서는 LSA기법을 이용하여 문서를 순차적으로 관리하고 유사한 지식을 그룹화 시키는 문서관리 알고리즘을 제안하고 사용자의 선호도에 맞는 알고리즘을 생성하기 위한 문서관리시스템을 설계한다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.70-72
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• 2002

전자우편(E-Mail)은 아주 편리한 통신수단이지만, 무분별한 광고성 스팸메일(Spam-Mail)의 침입과 무단으로 타인의 메일을 가로채거나 변조할 수 있기 때문에 메일의 신뢰성이 문제가 되고 있다. 본 연구에서는 이와 같은 문제를 해결하기 위하여 메일의 제목과 내용의 문자열을 분석하여 자동으로 스팸메일을 구분할 뿐만 아니라 보안도구인PGP(Pretty Good Privacy)를 이용하여 메일을 암호화하고 인증하여 근본적으로 스팸메일을차단하는 시스템을 개발한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.746-749
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• 2003

인터넷 사용자의 증가와 함께 e-mail 사용자 또한 증가하게 되면서 대량의 메일을 송수신하는 경우, 메일에 대한 효율적 관리의 중요성이 부각되고 있다. 본 논문에서는 수신된 메일의 내용을 텍스트 형태로 가져온 뒤, parallel regular expression을 이용하여 Keyword를 검색하고 추출하여 메일에 첨부되어온 멀티미디어 파일들을 자동으로 분류·저장하는 멀티미디어 첨부파일 자동분류 시스템을 제안하였다. 수신된 메일을 일일이 확인하고 분류해야만 했던 기존의 시스템과는 달리 본 논문에서 제안하고자 하는 시스템을 이용했을 경우 노력과 시간을 절감하고 첨부파일들을 효과적으로 관리할 수 있다는 장점이 있다.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.4
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• pp.247-258
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• 2009

Distributed file systems running on a cluster of inexpensive commodity hardware are being recognized as an effective solution to support the explosive growth of storage demand in large-scale Internet service companies. This paper presents the design and implementation of BeanFS, a distributed file system for large-scale e-mail services. BeanFS is adapted to e-mail services as follows. First, the volume-based replication scheme alleviates the metadata management overhead of the central metadata server in dealing with a very large number of small files. Second, BeanFS employs a light-weighted consistency maintenance protocol tailored to simple access patterns of e-mail message. Third, transient and permanent failures are treated separately and recovering from transient failures is done quickly and has less overhead.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.1
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• pp.13-20
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• 2006

In this paper, we constructed a spam-mail filtering system based on the lexical and conceptual information. There are two kinds of information that can distinguish the spam mail from the legitimate mil. The definite information is the mail sender's information, URL, a certain spam keyword list, and the less definite information is the word lists and concept codes extracted from the mail body. We first classified the spam mail by using the definite information, and then used the less definite information. We used the lexical information and concept codes contained in the email body for SVM learning. According to our results the spam precision was increased if more lexical information was used as features, and the spam recall was increased when the concept codes were included in features as well.