• The KIPS Transactions:PartC
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• v.12C no.6 s.102
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• pp.827-838
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• 2005

DDoS (Distributed Denial of Service) attack is a critical threat to current Internet. To solve the detection and response of DDoS attack on BcN, we have investigated detection algorithms of DDoS and Implemented anomaly detection modules. Recently too many technologies of the detection and prevention have developed, but it is difficult that the IDS distinguishes normal traffic from the DDoS attack Therefore, when the DDoS attack is detected by the IDS, the firewall just discards all over-bounded traffic for a victim or absolutely decreases the threshold of the router. That is just only a method for preventing the DDoS attack. This paper proposed the mechanism of response for the legitimated clients to be protected Then, we have designed and implemented the statistic based system that has the automated detection and response functionality against DDoS on Linux Zebra router environment.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06d
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• pp.26-29
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• 2010

네트워크 대역폭 소모 위주로 발생했던 DDoS 공격이 최근에는 웹서비스 대상 시스템 부하 유발을 통해 가용성을 떨어뜨리는 응용계층에서의 DDoS 공격 위주로 발생하고 있다. 이러한 DDoS 공격에 대응하기 위해 History, IP 분산도, GRT, Behavior 기반 등 다양한 대응 메커니즘이 연구되고 있지만 연구초기 단계에 머물러 있다. 본 논문에서는 Admission Control 기반 DDoS 공격대응 메커니즘을 제안하고, 시스템 개발을 통해 성능을 검증하였다. 제안된 메커니즘은 지금까지 발생한 모든 응용계층 DDoS 공격유형에 대응 가능하며, 기존 Behavior 기반 대응기법은 오탐지 가능성이 있으나 제안하는 메커니즘은 오탐지가 발생하지 않는 장점이 있어, 상용 환경에 바로 적용할 수 있을 것으로 예상된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.363-367
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• 2009

From the recent, an big issue of the internet attack is DDoS(Distributed Denial of Service). Some government agencies and companies will buy Anti-DDoS SW for protect their their network system form DDoS attack. But We don't have any objective valuation standard of Anti-DDoS SW. So When you try to buy an Anti-DDoS SW, you can get only subjective Anti-DDoS SW information which from Anti-DDoS SW vender. Anti-DDoS SW market is getting bigger, so market needs objective valuation standard of Anti-DDoS SW for a fair evaluation. In this paper, we describe a part of Anti-DDoS SW performance tests in valuation standard of Anti-DDoS SW.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.21-24
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• 2004

Ad Hoc 네트워크는 이동 노드만으로 구성된 자율/수평적 네트워크로서, 이동 노드는 중재자의 도움 없이 능동적인 연결 선정을 통해 무선 네트워크 환경을 제공한다. 이와 같은 Ad Hoc 네트워크에서도 일반적인 유선 기반 네트워크와 동일하게 서비스 거부 공격(DoS)이 가능하다. DDoS은 해킹 공격자가 공격 근원지 IP 주소를 스누핑하여 공격목표로 하는 시스템의 가용자원을 고갈시키거나 과도한 부하를 유발시켜 서비스를 중단시킨다. 이에 대한 대응 기술로 제시된 IP 역추적 기술은 DDoS 공격의 근원지를 판별하고 공격 패킷이 네트워크 상에서 전달된 경로를 재구성하는 기법이다 본 연구에서는 기존의 역추적 기술인 패킷 마킹 기법에서 DDoS 공격에 대한 판별 과정 없이 임의의 패킷에 대해 역추적 정보를 생성 즉 DDoS 공격에 능동적으로 대응하고 있지 못하는 단점에 착안하여 DDoS 공격 패킷에 대해 개선된 패킷 마킹 기법을 제시하고, 또한 TTL을 통하석 스누핑된 IP 근원지를 효율적으로 역추적하는 방안을 제시하였으며. 실험 결과 네트워크 부하를 줄이면서도 역추적 성능을 향상시킬 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1720-1726
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• 2011

The DDoS attacks which are increasing recently must have many zombie PCs before attacking targeted systems by attacker. A zombie PC is infected by attacker's malignant code and may be operated by the his/her special malicious purposes. But most users generally don't know that their PCs are infected and used as zombies by illegal activities covertly. In this paper, we propose a new scheme that decreases vulnerable PCs and isolates them from Internet before being zombie PCs. The proposed scheme point the reputations of connected PCs and decide whether their Internet connections are keeping continuously or not. Also We show the figures how to infect susceptable PCs to zombie PCs, and analyze the decrease effects of DDoS attacks adapted by the proposed scheme with various experiments.

• Convergence Security Journal
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• v.11 no.6
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• pp.25-30
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• 2011

MANET has a weak construction in security more because it is consisted of only moving nodes and doesn't have central management system. The DDoS attack is a serious attack among these attacks which threaten wireless network. The DDoS attack has various object and trick and become intelligent. In this paper, we propose the technique to raise DDoS detection rate by classifying abnormal traffic pattern. Cluster head performs sentinel agent after nodes which compose MANET are made into cluster. The decision tree is applied to detect abnormal traffic pattern after the sentinel agent collects all traffics and it judges traffic pattern and detects attack also. We confirm high attack detection rate of proposed detection technique in this study through experimentation.

• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.711-718
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• 2004

Packet sampling is the techniques to collect a part of the packets through network and analyze the characteristicsof the traffic for managing the network and keeping security. This paper presents a study on the sampling techniques applied to DDoS traffic and on the characteristics of the sampled traffic to detect DDoS attack efficiently and improve traffic analysis capacity. Three famous sampling techniques are evaluated with different sampling rates on various DDoS traffics. To analyze traffic characteristics, one of the DDoS attack detection method. Traffic Rate Analysis (TRA) is used. Simulation results verify that using sampling techniques preserve the traffic characteristics of DDoS and do not significantly reduce the detection accuracy.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.203-209
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• 2014

Today, Distributed denial of service (DDoS) attack present a very serious threat to the stability of the internet. The DDoS attack, which is consuming all of the computing or communication resources necessary for the service, is known very difficult to protect. The DDoS attack usually transmits heavy traffic data to networks or servers and they cannot handle the normal service requests because of running out of resources. It is very hard to prevent the DDoS attack. Therefore, an intrusion detection system on large network is need to efficient real-time detection. In this paper, we propose the detection mechanism using analysis of flow information against DDoS attacks in order to guarantee the transmission of normal traffic and prevent the flood of abnormal traffic. The OPNET simulation results show that our ideas can provide enough services in DDoS attack.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1477-1480
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• 2000

분산서비스거부(Distributed Denial of Service or DDoS)틀 이용한 공격은 공격목표시스템이 보안이 철저하다고 해도 쉽게 공격을 가할 수 있는 공격법이다. 근래에 들어 이러한 공격법은 여러 해킹 툴의 보급과 함께 급격히 증가하고 있다. 하지만, 시스템 자체의 보안만으로 대처 방안이 되지 못하고 있는 실정이다. DDoS 공격을 방지하기 위해서는 전체 시스템들이 모두 보안체계를 갖추고 있어야 하지만, 이것은 현실적으로 불가능하다. 결국 DDoS 공격을 탐지하고 대처하기 위해서는 라우터와 네트워크를 기반으로 한 대응시스템 설계가 요구된다. 또한 DDoS 공격의 재발을 막기 위해서는 DDoS 공격 시스템으로 이용된 시스템을 찾아 악성프로그램을 탐지하고 제거할 수 있는 악성에이전트 탐지 및 제거 시스템을 설계하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6845-6848
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• 2014

This paper proposes a system design of IDS for detecting and defending against DDoS attacks on a network. The proposed system has three parts; the Alert, Attack Analyzer and Defense agent. When the server resource was reduced too much by incoming traffic, the Alert Agent sends message and traffic information to the Attack Analyzer. The message and traffic to the Attack analyzer include only the sender & receiver address and packet numbers for minimizing the overload of Attack Analyzer. Message Received Attack Analyzer investigates the Message. If the pattern of traffic is the same as the DDoS Style, the Analyzer sends a message to the Defense Agent to block that traffic. In this system, at the serious state of the server-down, the Attack analyzer uncovers the DDoS Attacker and send a message to the Defense Agent to block that traffic. This works for server reactivation as soon as possible.