• 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.

• 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.

• 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 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.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.6
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• pp.1605-1618
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• 2016

In recent years, security incidents - such as personal information leakage, homepage hacking, DDoS and etc. - targeting finance companies(banks, securities companies, credit card companies, insurance companies and etc.) have increased steadily. In this paper, we analyze problems of information security management level in the existing electronic financial infrastructure from perspective of compliance and information security certification system and propose improvements to enable sustainable high level of information security activities under a comprehensive management system for the financial sector characteristics using ISMS, SECU-STAR and CNIVAM system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2555-2562
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• 2009

The algorithm that is proposed in this paper defined a probability function to count connection process and connection-end process to apply TRW algorithm to voice network. Set threshold to evaluate the algorithm that is proposed, Based on the type of connection attack traffic changing the probability to measure the effectiveness of the algorithm, and Attack packets based on the speed of attack detection time was measured. At the result of evaluation, proposed algorithm shows that DDoS attack starts at 10 packets per a second and it detects the attack after 1.2 seconds from the start. Moreover, it shows that the algorithm detects the attack in 0.5 second if the packets were 20 per a second.

• Review of KIISC
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• v.15 no.2
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• pp.74-82
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• 2005

오늘날 네트워크 보안 기술은 해커의 침입 탐지 및 제어, 분산 서비스 거부 공격의 방지 등 많은 분야에서 발전하여 왔다. 그러나, 최근 많은 문제를 발생시키면서 등장한 인터넷 웜은 기존의 네트워크 보안 장비들을 무력화시키며 인터넷 상에 연결된 많은 호스트들을 감염시키고 동시에 네트워크 자원을 소모시켜 버렸다. 실상 초기의 웜은 작은 규모의 네트워크에서 퍼지는 정도 일뿐 심각한 피해를 주는 경우는 거의 없었고 따라서 이에 대해서 심각한 대비책 등을 생각하지는 않았다. 그러나 2001년 발생한 CodeRed 웜은 인터넷에 연결된 많은 컴퓨터들을 순식간에 감염시켜 많은 경제적, 물질적 피해를 발생시켰고, 그 이후 2003년 1월에 발생한 Stammer 웜은 10분이라는 짧은 순간 안에 75000 여대 이상의 호스트를 감염시키고 네트워크 자체를 마비시켰다. 특히 Stammer 월은 국내에서 많은 피해를 유발시켰기에 더더욱 유명하다. 명절 구정과 맞물려 호황을 누리던 인터넷 쇼핑 몰과, 인터넷 금융 거래를 수행하던 은행 전산소 등을 일시에 마비시켜 버리면서 경제적으로도 실질적인 막대한 피해를 우리에게 주었다. 이런 웜을 막기 위해서 많은 보안 업체 및 연구소들이 나서고 있으나, 아직은 사전에 웜의 피해를 막을만한 확실한 대답을 얻지 못하고 있다. 본 논문에서는, 현재 수행하고 있는 여러 웜의 탐지기법에 대해서 조사한 결과를 설명하고, 이어서 본 연구소에서 수행하고 있는 웜의 탐지 기법에 대해서 설명하고 간단한 탐지 결과를 보일 것이다.

• The Korean Journal of Applied Statistics
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• v.26 no.2
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• pp.291-305
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• 2013

Collective traffic data (BPS, PPS etc.) for detection against the distributed denial of service attack on network is the time sequencing big data. The algorithm to detect the change point in the big data should be accurate and exceed in detection time and detection capability. In this work, the sliding window and discretization method is used to detect the change point in the big data, and propose five nonparametric test statistics using empirical distribution functions and ranks. With various distribution functions and their parameters, the detection time and capability including the detection delay time and the detection ratio for five test methods are explored and discussed via monte carlo simulation and illustrative examples.

• Journal of the Korea Society of Computer and Information
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• v.15 no.9
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• pp.99-107
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• 2010

This paper showed that the integrated system to fortify security was much more efficient than the respective system through the analysis of problems from Firewall and IPS system in the existing security systems. The results of problem analysis revealed that there were the delay of processing time and lack of efficiency in the existing security systems. Accordingly, their performance was evaluated by using the separated Firewall, IPS system, and the integrated system. The result of evaluation shows that the integrated security system this paper suggested is five times faster than the existing one in terms of processing speed of response. This paper demonstrated the excellence of the proposed security system is also more than fivefold in session handling per second and six times process speeding in the CPU processing performance. In addition, several security policies are applied, and it provided a fact that it gave an excellent performance when it comes to protecting from harmful traffic attacks. In conclusion, this paper emphasized that fortifying the integrated security system was more efficient than fortifying the existing one considering in various respects such as cost, management, time, space and so on.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.22-30
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• 2020

With the development of information and communication technology, DDoS and DRDoS continue to become security issues, and gradually develop into advanced techniques. Recently, IT companies have been threatened with DRDoS technology, which uses protocols from normal servers to exploit as reflective servers. Reflective traffic is traffic from normal servers, making it difficult to distinguish from security equipment and amplified to a maximum of Tbps in real-life cases. In this paper, after comparing and analyzing the DNS amplification and Memcached amplification used in DRDoS attacks, a countermeasure that can reduce the effectiveness of the attack is proposed. Protocols used as reflective traffic include TCP and UDP, and NTP, DNS, and Memcached. Comparing and analyzing DNS protocols and Memcached protocols with higher response sizes of reflective traffic among the protocols used as reflective traffic, Memcached protocols amplify ±21% more than DNS protocols. The countermeasure can reduce the effectiveness of an attack by using the Memcached Protocol's memory initialization command. In future studies, various security-prone servers can be shared over security networks to predict the fundamental blocking effect.