Corporate mail services are designed to perform better than public mail services. Fast mail delivery, large size file transfer as an attachments, high level spam and virus protection, commercial advertisement free environment are some of the advantages worth to mention. But these mail services are frequent target of hackers and spammers. Distributed Denial of service attacks are becoming more c...

Distributed denial of service (DDoS) attacks on the Internet have become an immediate problem. As DDoS streams do not have common characteristics, currently available intrusion detection systems (IDS) cannot detect them accurately. As a result, defend DDoS attacks based on current available IDS will dramatically affect legitimate traffic. In this paper, we propose a distributed approach to defe...

As the complexity of Internet is scaled up, it is likely for the Internet resources to be exposed to Distributed Denial of Service (DDoS) flooding attacks on TCP-based Web servers. There has been a lot of related work which focuses on analyzing the pattern of the DDoS attacks to protect users from them. However, none of these studies takes all the flags within TCP header into account, nor do th...

Intrusion tolerance is the ability of a system to continue providing (possibly degraded but) adequate services after a penetration. With the rapid development of network technology, distributed denial of service (DDoS) attacks become one of the most important issues today. In this paper, we propose a DDoS ontology to provide a common terminology for describing the DDoS models consisting of the ...

Traffic matrix-based anomaly detection and DDoS attacks detection in networks are research focus in the network security and traffic measurement community. In this paper, firstly, a new type of unidirectional flow called IF flow is proposed. Merits and features of IF flows are analyzed in detail and then two efficient methods are introduced in our DDoS attacks detection and evaluation scheme. T...

Nowadays, Distributed Denial-of-Service (DDoS) attacks are a major threat for all sizes of networks. The number of attacks against companies and institutions steadily increased over the last years. Downtime of an enterprise network usually causes financial damage. Therefore, it is important to have mechanism for DDoS defense. In this paper, various DDoS defense mechanisms are reviewed and compa...

In this paper, we present Nyx, the first system to both effectively mitigate modern Distributed Denial of Service (DDoS) attacks regardless of the amount of traffic under adversarial control and function without outside cooperation or an Internet redesign. Nyx approaches the problem of DDoS mitigation as a routing problem rather than a filtering problem. This conceptual shift allows Nyx to avoi...

Nowadays, users can easily access and download network attack tools, which often provide friendly interfaces and easily operated features, from the Internet. Therefore, even a naive hacker can also launch a large scale DoS or DDoS attack to prevent a system, i.e., the victim, from providing Internet services. In this paper, we propose an agent based intrusion detection architecture, which is a ...

Flooding-based distributed denial-of-service (DDoS) attack presents a very serious threat to the stability of the Internet. In a typical DDoS attack, a large number of compromised hosts are amassed to send useless packets to jam a victim, or its Internet connection, or both. In the last two years, it is discovered that DDoS attack methods and tools are becoming more sophisticated, effective, an...

The key objective of a Distributed Denial of Service (DDoS) attack is to compile multiple systems across the Internet with infected zombies/agents and form botnets of networks. Such zombies are designed to attack a particular target or network with different types of packets. The infected systems are remotely controlled either by an attacker or by self-installed Trojans (e.g. roj/Flood-IM) that...