Collaborative Detection of DDoS Attacks over Multiple Network Domains

This paper presents a new distributed approach to detecting DDoS (distributed denial of services) flooding attacks at the traffic-flow level The new defense system is suitable for efficient implementation over the core networks operated by Internet service providers (ISPs). At the early stage of a DDoS attack, some traffic fluctuations are detectable at Internet routers or at the gateways of edge networks. We develop a distributed change-point detection (DCD) architecture using change aggregation trees (CAT). The idea is to detect abrupt traffic changes across multiple network domains at the earliest time. Early detection of DDoS attacks minimizes the floe cling damages to the victim systems serviced by the provider. The system is built over attack-transit routers, which work together cooperatively. Each ISP domain has a CAT server to aggregate the flooding alerts reported by the routers. CAT domain servers collaborate among themselves to make the final decision. To resolve policy conflicts at different ISP domains, a new secure infrastructure protocol (SIP) is developed to establish mutual trust or consensus. We simulated the DCD system up to 16 network domains on the Cyber Defense Technology Experimental Research (DETER) testbed, a 220-node PC cluster for Internet emulation experiments at the University of Southern California (USC) Information Science Institute. Experimental results show that four network domains are sufficient to yield a 98 percent detection accuracy with only 1 percent false-positive alarms. Based on a 2006 Internet report on autonomous system (AS) domain distribution, we prove that this DDoS defense system can scale well to cover 84 AS domains. This security coverage is wide enough to safeguard most ISP core networks from real-life DDoS flooding attacks.     

MANET中分布式拒绝服务攻击研究综述

随着移动自组织网络在各个领域内得到广泛的使用,其安全性研究显得越来越重要。DDoS攻击给有线网络造成了很大的威胁,同样也威胁到了移动自组织网络的安全性。由于移动自组织网络和有线网络存在着结构型差异,因此移动自组织网络中的DDoS攻击研究与有线网络中的DDoS攻击研究有较大的不同。论文首先描述了移动自组织网络的安全状况;然后从移动自组织网络的网络架构出发,分别分析移动自组织网络中针对物理层、MAC层、网络层以及传输层的DDoS攻击,同时总结针对不同网络层次的攻击所需要采取的防御措施;最后为移动自组织网络建设过程中就如何防范DDoS攻击提出参考意见。     

DDoS attack protection in the era of cloud computing and Software-Defined Networking

Cloud computing has become the real trend of enterprise IT service model that offers cost-effective and scalable processing. Meanwhile, Software-Defined Networking (SDN) is gaining popularity in enterprise networks for flexibility in network management service and reduced operational cost. There seems a trend for the two technologies to go hand-in-hand in providing an enterprise’s IT services. However, the new challenges brought by the marriage of cloud computing and SDN, particularly the implications on enterprise network security, have not been well understood. This paper sets to address this important problem.We start by examining the security impact, in particular, the impact on DDoS attack defense mechanisms, in an enterprise network where both technologies are adopted. We find that SDN technology can actually help enterprises to defend against DDoS attacks if the defense architecture is designed properly. To that end, we propose a DDoS attack mitigation architecture that integrates a highly programmable network monitoring to enable attack detection and a flexible control structure to allow fast and specific attack reaction. To cope with the new architecture, we propose a graphic model based attack detection system that can deal with the dataset shift problem. The simulation results show that our architecture can effectively and efficiently address the security challenges brought by the new network paradigm and our attack detection system can effectively report various attacks using real-world network traffic.     

一种基于客户端网络的DDoS攻击防卫模型的研究

分布式拒绝服务攻击(DDoS)严重威胁着因特网的安全，但目前没有一种有效的方法来对付这种攻击。我们提出了一种基于客户端网络的DDoS攻击防卫模型--E-GUARD，它能够自动监测和停止源于本地网络的DDoS攻击。     

Defending against Distributed Denial of Service Attacks: Issues and Challenges

ABSTRACT

Distributed Denial of Service (DDoS) attacks on user machines, organizations, and infrastructures of the Internet have become highly publicized incidents and call for immediate solution. It is a complex and difficult problem characterized by an explicit attempt of the attackers to prevent access to resources by legitimate users for which they have authorization. Several schemes have been proposed on how to defend against these attacks, yet the problem still lacks a complete solution. The main purpose of this paper is therefore twofold. First is to present a comprehensive study of a wide range of DDoS attacks and defense methods proposed to combat them. This provides better understanding of the problem, current solution space, and future research scope to defend against DDoS attacks. Second is to propose an integrated solution for completely defending against flooding DDoS attacks at the Internet Service Provider (ISP) level.     

基于验证与自主学习的主动DDoS防御系统

主动DDoS防御系统(ADDS)主要防御基于网络的DDoS攻击。使用体系防御技术组织防火墙、路由器和中心主机共同防御,弥补了防火墙、路由器和内核级防御程序单独防御的不足;使用分区超时技术使系统具有快速防御DDoS的能力;使用流量分析技术控制路由器,优化网络流量分配;使用连接验证技术消除傀儡机的攻击。多种技术和多层次的防御使系统具有较强的防御DDoS攻击能力。     

一种防御DDoS攻击的软件定义安全网络机制

软件定义网络的出现为防御DDoS攻击提供了新的思路.首先,从网络体系结构角度建模分析了DDoS攻击所需的3个必要条件：连通性、隐蔽性与攻击性;然后,从破坏或限制这些必要条件的角度出发,提出了一种能够对抗DDoS攻击的软件定义安全网络机制SDSNM（software defined security networking mechanism）.该机制主要在边缘SDN网络实现,同时继承了核心IP网络体系架构,具有增量部署特性.利用云计算与Chord技术设计实现了原型系统,基于原型系统的测量结果表明,SDSNM具有很好的扩展性和可用性.     

DoS-DDoS: TAXONOMIES OF ATTACKS,COUNTERMEASURES, AND WELL-KNOWN DEFENSE MECHANISMS IN CLOUD ENVIRONMENT

Cloud computing has become a suitable provider of services for organizations as well as individuals through the Internet. Generally, these services become unavailable because of Denial of Service (DoS) and Distributed Denial of Service (DDoS) attacks that can deny the legitimate users access to the service delivered by cloud. Taxonomy is an important opportunity for researchers and cloud service providers. Therefore, it provides researchers with a general view about some contributions to understand and ameliorate their limitations and helps cloud service providers to select the best defense strategy to protect their cloud service against DoS and DDoS attacks. In this article, we present taxonomies of DoS and DDoS attacks in cloud environment, countermeasures, and highlight their solutions with another taxonomy of well-known defense mechanisms.     

Malicious node prevention and mitigation in MANETs using a hybrid security model

Mobile ad-hoc network (MANET) has got tremendous success and attention due to its self-maintenance and self-configuration properties or behavior. Based on wired and wireless networks, the network topology of MANETs changes rapidly by means of routing attacks. Hence, providing security to this infrastructure-less network is a major issue. The routing protocols for ad-hoc networks cope well with the dynamically changing topology but are not designed to accommodate defense against malicious attacker. Malicious nodes have opportunities to modify or discard routing information or advertise fake routes to attract user data to go through themselves. In this article, we discuss a hybrid technique using anonymity, one-way trapdoor protocol, hash functions, and elliptic curve cryptographic to mitigate attacks in the MANET. The simulation is carried on NS-2 and the simulation results are dissected on different system execution measurements, for example, packet send and received, packet dropped, average network throughput, end-to-end delay, and packet delivery ratio.     

Fast autonomous system traceback

Service-oriented computing (SOC) due to their distributed and lose coupled nature are very vulnerable to distributed denial of service (DDoS) attacks. IP spoofing makes it difficult for the victim to determine the packet's origin. There is a need for a mechanism that could enable real-time traceback of the origins of the attacks. In this paper, we propose a novel protocol, fast autonomous system traceback (FAST) to traceback to the attack originating autonomous systems (AS). The multifold advantages of FAST include reconstruction requires just around 5–10 packets and reconstruction takes just a few seconds. We validate the performance through extensive simulations over the datasets obtained from traceroute.     

剖析DDoS攻击对抗技术

由于目前Internet的体系结构、认证机制的缺乏等多方面原因使得DDoS攻击很容易发生,而且僵尸网络的快速发展也为DDoS攻击提供了强大的工具。DDoS(Distributed Denial of Service)攻击一直是网络安全的主要威胁之一,如何对抗DDoS攻击成为网络安全研究的热点之一。在对DDoS攻击模型、产生原因进行分析的基础上,从攻击预防、攻击检测、攻击响应和攻击源追踪四个方面对现有的DDoS攻击对抗技术进行综述,并提出了值得研究的方向建议。     

DDoS攻击防御机制综述

DDoS攻击是目前威胁网络安全的主要因素之一。本文分类介绍了现有的DDoS攻击防御机制,阐明了各种机制之间的关系,给出了每种防御机制的应用实例,全面分析了各种防御机制的优缺点。对正确认识DDoS攻击及其防御有很大的参考价值。     

Agent system for inter-AS routing error diagnosis

The basic unit of Internet routing is called an autonomous system, or AS, defined as a set of routers under a single technical administration. The Internet currently comprises more than 12,000 AS's. Some are university or corporate networks; others are ISP networks. Inside an AS, a single authority controls the deployment of policies and protocols by which routers compute intra-AS paths, including paths to gateway or border routers. For inter-AS routing, the situation is more complicated. Most AS's manage the exchange of routing information through the Internet Engineering Task Force's border gateway protocol. BGP lets an AS advertise "reachability" information throughout the Internet by sending update information when network topology or routing policies change. BGP is a hop-by-hop protocol, which sends the information only to a gateway router's immediate neighbors. At NTT Network Innovation Laboratories, we have developed and are currently testing a multiagent-based system called Encore to automatically diagnose inter-AS routing problems. We briefly describe the problem addressed by the system, its design and current implementation, and recent test results     

一种防御DDoS攻击的集成方法

防御DDoS攻击是网络安全的一个重要研究领域，在该领域已有许多方法，例如：源端检测，地址跟踪，数据包分类，流量检测。但是，每种方法都有它的特点和应用局限。文章运用分级防御的思想提出了一种集成方法。“集成”的意思是指把若干体系的方法集成在一起，使其成为一个新的功能更强的防御体系。该防御系统具有可靠性高、响应速度快、对合法数据包影响小等特点。     

Distributed Denial of Service Attacks: A Threat or Challenge

In today’s cyber world, the Internet has become a vital resource for providing a plethora of services. Unavailability of these services due to any reason leads to huge financial implications or even consequences on society. Distributed Denial of Service (DDoS) attacks have emerged as one of the most serious threats to the Internet whose aim is to completely deny the availability of different Internet based services to legitimate users. The attackers compromise a large number of Internet enabled devices and gain malicious control over them by exploiting their vulnerabilities. Simplicity of launching, traffic variety, IP spoofing, high volume traffic, involvement of numerous agent machines, and weak spots in Internet topology are important characteristics of DDoS attacks and makes its defense very challenging. This article provides a survey with the enhanced taxonomies of DDoS attacks and defense mechanisms. Additionally, we describe the timeline of DDoS attacks to date and attempt to discuss its impact according to various motivations. We highlighted the general issues, challenges, and current trends of DDoS attack technology. The aim of the article is to provide complete knowledge of DDoS attacks and defense mechanisms to the research community. This will, in turn, help to develop a powerful, effective, and efficient defense mechanism by filling the various research gaps addressed in already proposed defense mechanisms.     

分布式拒绝服务攻击防御技术研究

分布式拒绝服务攻击已成为影响Internet的重要攻击手段,总结了近年来检测防御技术的研完成果,对分布式拒绝服务检测防御技术进行了分类,并详细分析了防御技术。对防御分布式拒绝服务攻击提供了很大的参考价值。     

Securing Cooperative Ad-Hoc Networks Under Noise and Imperfect Monitoring: Strategies and Game Theoretic Analysis

In cooperative ad-hoc networks, nodes belong to the same authority and pursue the common goals, and will usually unconditionally help each other. Consequently, without necessary countermeasures, such networks are extremely vulnerable to insider attacks, especially under noise and imperfect monitoring. In this paper, we present a game theoretic analysis of securing cooperative ad-hoc networks against insider attacks in the presence of noise and imperfect monitoring. By focusing on the most basic networking function, namely routing and packet forwarding, we model the interactions between good nodes and insider attackers as secure routing and packet forwarding games. The worst case scenarios are studied where initially good nodes do not know who the attackers are while insider attackers know who are good. The optimal defense strategies have been devised in the sense that no other strategies can further increase the good nodes' payoff under attacks. Meanwhile, the optimal attacking strategies and the maximum possible damage that can be caused by attackers have been discussed. Extensive simulation studies have also been conducted to evaluate the effectiveness of the proposed strategies     

减弱DDoS攻击的策略研究

DDoS攻击是目前威胁网络安全的主要因素之一.除非修改TCP/IP的内核,否则,从理论上没有办法彻底解决,但通过一些技术手段,可以有效地阻止一些DDoS攻击,降低攻击的危害.基于这一观点,总结并分析了现有的减弱DDoS攻击危害的防御机制,并在仿真环境中验证了算法的有效性,对进一步认识DDoS攻击及其防御具有参考价值.     

A routing defense mechanism using evolutionary game theory for Delay Tolerant Networks

Delay Tolerant Networks (DTNs) often suffer from intermittent disruption due to factors such as mobility and energy. Though lots of routing algorithms in DTNs have been proposed in the last few years, the routing security problems have not attracted enough attention. DTNs are still facing the threats from different kinds of routing attacks. In this paper, a general purpose defense mechanism is proposed against various routing attacks on DTNs. The defense mechanism is based on the routing path information acquired from the forwarded messages and the acknowledgment (ACK), and it is suitable for different routing schemes. Evolutionary game theory is applied with the defense mechanism to analyze and facilitate the strategy changes of the nodes in the networks. Simulation results show that the proposed evolutionary game theory based defense scheme can achieve high average delivery ratio, low network overhead and low average transmission delay in various routing attack scenarios. By introducing the game theory, the networks can avoid being attacked and provide normal transmission service. The networks can reach evolutionary strategy stable (ESS) under special conditions after evolution. The initial parameters will affect the convergence speed and the final ESS, but the initial ratio of the nodes choosing different strategies can only affect the game process.     

基于协议分析技术的网络入侵检测系统中DDoS攻击的方法研究

随着网络技术的发展,网络环境变得越来越复杂,对网络安全来说,单纯的防火墙技术暴露出明显的不足和弱点,包括无法解决安全后门问题,不能阻止网络内部攻击等问题。在众多的网络安全威胁中,DDoS攻击以其实施容易,破坏力度大,检测困难等特点而成为网络攻击检测与防御的重中之重。近年来,针对网络流量相关性的DDoS攻击检测方法层出不穷,文章在分析DDoS攻击检测方法的基础上,利用基于协议分析技术的网络入侵检测系统对DDoS进行研究。