Over the past few years, denial-of-service (DoS) and distributed denial-of-service (DDoS) attacks have become more of a threat than ever. These attacks are aimed at denying or degrading service for a legitimate user by any means necessary. The need to propose and research novel methods to mitigate them has become a critical research issue in network security. Recently, client puzzle protocols h...

Distributed denial of service (DDoS) attacks are widely regarded as a major threat to the Internet. A flooding-based DDoS attack is a very common way to attack a victim machine by sending a large amount of malicious traffic. Existing networklevel congestion control mechanisms are inadequate in preventing service quality from deteriorating because of these attacks. Although a number of technique...

Various cryptographic puzzle schemes have been proposed as defenses against Denial of Service (DoS) attacks. However, these schemes have two common shortcomings that diminish their effectiveness as a DoS mitigation solution. First, the DoS-resilience that these schemes provide is minimized when there is a large disparity between the computational power of malicious and legitimate clients. Secon...

In present era, the world is highly dependent on the Internet and it is considered as main infrastructure of the global information society. Therefore, the Availability of information and services is very critical for the socio-economic growth of the society. However, the inherent vulnerabilities of the Internet architecture provide opportunities for a lot of attacks on its infrastructure and s...

This paper investigates the effectiveness of rate-limiting in mitigating TCP-based flooding Denial of Service (DoS) attacks. Rate-limiting is used as a DoS defense mechanism to discard a fraction of incoming attack packets. Part of legitimate traffic is, however, mis-detected as attack traffic. The main contribution of this paper is to find out how much a DoS attack can be rate-limited without ...

Volumetric Distributed Denial of Service (DDoS) attacks have been a recurrent issue on the Internet. These attacks generate a flooding of fake network traffic to interfere with targeted servers or network links. Despite many efforts to detect and mitigate them, attackers have played a game always circumventing countermeasures. Today, there is an increase in the number of infected devices, even ...

One of the challenging tasks on the Internet is differentiating the attack traffic from legitimate traffic. Tackling this challenge would aid in the detection of Denial of Service/Distributed DoS (DoS/DDoS) attacks. In this paper, we propose a flow profiling scheme that adopts itself to detect these flooding attacks by monitoring the trends in the current traffic. Moreover, our scheme filters m...

We have recently witnessed the real life demonstration of link-flooding attacks—DDoS attacks that target the core of the Internet that can cause significant damage while remaining undetected. Because these attacks use traffic patterns that are indistinguishable from legitimate TCP-like flows, they can be persistent and cause long-term traffic disruption. Existing DDoS defenses that rely on dete...

______________________________________________________________________________________ Abstract— Adhoc Networks (MANETs) are an emerging area of mobile computing. There are various challenges that are faced in adhoc environment. These are mostly due to the resource poorness of these networks. They are usually set up in situations of emergency, for temporary operations or simply if there are no ...

v Abstract With the emergence of mobile multimedia services, such as unified messaging, click to dial, cross network multiparty conferencing and seamless multimedia streaming services, the fixed–mobile convergence and voice–data integration has started, leading to an overall Internet–Telecommunications merger. The IP Multimedia Subsystem (IMS) is considered as the next generation service delive...