• Journal of KIISE:Information Networking
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• v.31 no.5
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• pp.438-449
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• 2004

With the growing deployment of network and internet, the importance of security is also increased. But, recent intrusion detection systems which have an important position in security countermeasure can't provide proper analysis and effective defence mechanism. Instead, they have overwhelmed human operator by large volume of intrusion detection alerts. In this paper, we propose an efficient alert analysis system that can produce high level information by analyzing and processing the large volume of alerts and can detect large-scale attacks such as DDoS in early stage. And we have measured processing rate of each elementary module and carried out a scenario-based test in order to analyzing efficiency of our proposed system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5256-5262
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• 2014

Recently, Distributed Denial of Service (DDoS) attacks, such as spreading malicious code, cyber-terrorism, have occurred in government agencies, the press and the financial sector. DDoS attacks are the simplest Internet-based infringement attacks techniques that have fatal consequences. DDoS attacks have caused bandwidth consumption at the network layer. These attacks are difficult to detect defend against because the attack packets are not significantly different from normal traffic. Abnormal traffic is threatening the stability of the network. Therefore, the abnormal traffic by generating indications will need to be detected in advance. This study examined the abnormal traffic detection technique using a forecasting model-based trend model.

• Convergence Security Journal
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• v.16 no.5
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• pp.11-16
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• 2016

In modern society, the development of Information and Communication Technology has given people a lot of opportunities. But on the other side cyber attack also gives enormous damage to people. Recently Korea has become the target of cyber attack. The threat of it is growing. Especially North Korea has committed hostile actions against South Korea. North Korea has recently attacked the computer networks of South Korea's important national facilities. The types of North Korea's cyber attacks include the followings. First, if we see it with the viewpoint of software, it tries to destroy or control the Internet, infects the networks with viruses, worms, Trojan Horse and Distributed Denial of Service. I suggest the following to solve the problem. First, South Korea should unify the organizations to respond to the attacks of North Korea, as North Korea has a unified organization for the cyber attack. Second, they should think about the establishment of "Cyber Terrorism Prevention Act" to systematically respond to the software attacks.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.6
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• pp.689-694
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• 2014

DDoS attacks on MANET makes disable any node which support network function, cause critical results as a stopping of entire network service or separation to some parts. Packet aggregation, which gather some pieces of short length into a certain length of data, improves transmission performances on MANETs. In this paper, some effects on transmission performance of packet aggregation transmission be caused by DDoS Attacks are measured and analyzed in point of end-to-end level. MANET simulator, based on NS-2, is used for measurement end-to-end performances. MOS, connection rate, delay and packet loss rate is used as performance parameters. VoIP traffic is used for object service measurement. Finally, it is suggested that number of packet aggregation is more then 4 for keeping the transmission quality over MANETs under DDoS attacks.

• Review of KIISC
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• v.21 no.2
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• pp.36-46
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• 2011

지난 3월 4일 국내 일부 금융기관과 포털 사이트 등이 분산서비스거부 공격으로 접속이 중단되는 사태가 발생했다. 이번 사건뿐만 아니라 세계 곳곳에서는 범죄적 양상을 띠는 다양한 사이버 범죄 발생이 증가하고 있다. 이에 앞서 미 정부는2009년 "사이버스페이스 정책 리뷰(cyberspace policy review)"를 발표해 사이버보안의 책임 공유, 사이버보안 사고 발생시 긴밀한 대응을 위한 유관기관 간의 정보 공유 및 사고 대응을 위한 체계 구축 등의 전략을 내세운 바 있다. 이러한 전략의 연장선으로 예상되는 사이버보안에 대한 국제표준화 활동이 ITU-T SG17 Q.4에서 진행되고 있어 사이버보안 분야표준화 동향과 함께 Q.4의 주요 의제인 사이버보안 정보 교환 기술에 대한 정보를 제공하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.1024-1026
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• 2010

IT 기술의 발달로 자료의 대형화, 통신의 초고속 광역화가 이루어짐에 따라 우리 실생활과 비즈니스에 밀접하게 연관되어있을 뿐 만 아니라, 분산서비스거부(DDos)공격과 대규모 개인정보 유출사례 등은 데이터베이스(DB) 보안의 중요성은 한층 높아지고 있다. 본 논문에서는 대형 개인 정보 유출사고의 가능성을 안고 있는 기업에서 DB 암호화 구축 이후 발생할 수 있는 장애요소를 최소화 할 수 있도록 DB 보안 요구사항에 기반한 점검 항목을 도출하고 테스트 방안을 제시하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.695-696
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• 2009

최근 증가하고 있는 클라우드 컴퓨팅 환경에서는 동일한 하드웨어 플랫폼에서 운용되는 다수의 가상머신들이 악성코드에 감염되어 분산서비스거부 공격을 위한 좀비로 악용될 위험이 있다. 그러나, 기존의 가상머신에 대한 보안 기술은 악성코드 감염에 대해 능동적으로 대응하지 못하는 한계가 있다. 이에 따라 본 논문에서는 Xen 하이퍼바이저를 기반으로 구축된 클라우드 컴퓨팅 환경에서 다수의 가상머신이 악성코드에 감염되는 것을 차단하기 위한 보안 시스템의 설계 방법을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.1103-1106
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• 2005

IPv4 프로토콜의 주소 고갈 문제를 해결하기 위하여 IPv6 프로토콜이 제안되었고 한국전산원의 발표에 의하면 2010년 이후에는 IPv6 프로토콜이 광범위하게 사용될 것이라고 한다. 이러한 IPv6 프로토콜은 IPv4 프로토콜의 단점들을 해결하기 위하여 ND(Neighbor Discovery) 메커니즘, 주소자동설정, IPsec 등의 기술을 지원하며, 특히 IPv6 프로토콜은 보안 문제를 해결하기 위해서 인증, 데이터 무결성 보호를 위한 IPsec 기술을 사용한다. 이러한 IPsec 기술은 패킷 정보를 보호하기 위한 목적으로 사용되기 때문에 불특정 다수의 사용자를 대상으로 하는 네트워크에 행해지는 분산 서비스 거부 공격과 같은 비정상 대용량 트래픽에 대한 탐지 및 차단에 어려움이 있다. 현재 IPv6 프로토콜을 지원하는 네트워크 공격 대응 기술로 IPv6 네트워크용 방화벽/침입탐지 시스템이 개발되어 제품으로 판매되고 있지만, 대용량의 비정상 트래픽 대응 기술을 탐지하고 차단하기에는 한계가 있다. 본 논문에서는 IPv6 네트워크 환경에서 이러한 대용량의 비정상 트래픽을 제어할 수 있는 프레임워크를 제시한다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.4
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• pp.51-61
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• 2009

Recently, the cyber-attacks using botnets are being increased, Because these attacks pursue the money, the criminal aspect is also being increased, There are spreading of spam mail, DDoS(Distributed Denial of Service) attacks, propagations of malicious codes and malwares, phishings. leaks of sensitive informations as cyber-attacks that used botnets. There are many studies about detection and mitigation techniques against centralized botnets, namely IRC and HITP botnets. However, P2P botnets are still in an early stage of their studies. In this paper, we analyzed the traffics of the Peacomm bot that is one of P2P-based storm bot by using honeynet which is utilized in active analysis of network attacks. As a result, we could see that the Peacomm bot sends a large number of UDP packets to the zombies in wide network through P2P. Furthermore, we could know that the Peacomm bot makes the scale of botnet maintained and extended through these results. We expect that these results are used as a basis of detection and mitigation techniques against P2P botnets.

• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.65-75
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• 2009

The development of IT technology, Internet popularity is increasing geometrically. However, as its side effect, the intrusion behaviors such as information leakage for key system and infringement of computation network etc are also increasing fast. The attack traffic detection method which is suggested in this study utilizes the Snort, traditional NIDS, filters the packet with false positive among the detected attack traffics using Nmap information. Then, it performs the secondary filtering using nessus vulnerability information and finally performs correlation analysis considering appropriateness of management system, severity of signature and security hole so that it could reduce false positive alarm message as well as minimize the errors from false positive and as a result, it raised the overall attack detection results.