This paper proposes a methodology for detecting networklayer anomalies in wireless sensor networks using weak process models (WPM). Weak process models are a non-parametric version of Hidden Markov models (HMM), wherein state transition probabilities are reduced to rules of reachability. Specifically, we present an intrusion detection system based on anomaly detection logic. It identifies any o...

The goal of a distributed denial of service (DDoS) attack is to completely tie up certain resources so that legitimate users are not able to access a service. It has long been an open security problem of the Internet. In this paper, we identify a class of stateful DDoS attacks that defeat the existing cookie-based solutions. To counter these attacks, we propose a new defense mechanism, called t...

Denial of Service (DoS) is a security threat which compromises the confidentiality of information stored in Local Area Networks (LANs) due to unauthorized access by spoofed IP addresses. SYN Flooding is a type of DoS which is harmful to network as the flooding of packets may delay other users from accessing the server and in severe cases, the server may need to be shut down, wasting valuable re...

This thesis presents a novel approach to provide adaptive mechanisms to detect and categorise Flooding-Base DoS (FBDoS) and Flooding-Base DDoS (FBDDoS) attacks. These attacks are generally based on a flood of packets with the intention of overfilling key resources of the target, and today the attacks have the capability to disrupt networks of almost any size. To address this problem we propose ...

Many ad hoc routing algorithms rely on broadcast flooding for location discovery or, more generally, for secure routing applications. Flooding is a robust algorithm but because of its extreme redundancy, it is impractical in dense networks. Indeed in large wireless networks, the use of flooding algorithms may lead to broadcast storms where the number of collisions is so large that it causes sys...

There are two statistical decision making questions regarding statistically detecting sings of denial-of-service flooding attacks. One is how to represent the distributions of detection probability, false alarm probability and miss probability. The other is how to quantitatively express a decision region within which one may make a decision that has high detection probability, low false alarm p...

We present Robin, an attack-resilient microblogging service, designed to provide citizens of an oppressive regime, the ability to disseminate messages during periods of complete communication blackouts imposed by the government. Using a delaytolerant network comprised solely of smart-phones, messages are relayed opportunistically among citizens. Our key contribution is a novel mechanism to prot...

Although the prevention of Distributed Denial of Service (DDoS) attacks is not possible, detection of such attacks plays main role in preventing their progress. In the flooding attacks, especially new sophisticated DDoS, the attacker floods the network traffic toward the target computer by sending pseudo-normal packets. Therefore, multi-purpose IDSs do not offer a good performance (and accuracy...

The Optimized Link State Routing Protocol is developed for Mobile Ad Hoc Network. It operates as a table driven, proactive protocol. The core of the OLSR protocol is the selection of Multipoint Relays (MPRs), used as a flooding mechanism for distributing control traffic messages in the network, and reducing the redundancy in the flooding process. A node in an OLSR network selects its MPR set so...

The rate of acceptance of clouds each year is making cloud computing the leading IT computational technology. While cloud computing can be productive and economical, it is still vulnerable to different types of external threats, one of which is a Denial of Service (DoS) attack. Taking the cloud providers’ security services could cause disputes and involvement of hidden costs. Rather than depend...