8,023 research outputs found

    Networked Control Under DoS Attacks:Tradeoffs Between Resilience and Data Rate

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    In this article, we study communication-constrained networked control problems for linear time-invariant systems in the presence of Denial-of-Service (DoS) attacks, namely attacks that prevent transmissions over the communication network. Our article aims at exploring the tradeoffs between system resilience and network bandwidth capacity. Given a class of DoS attacks, we characterize the bit-rate conditions that are dependent on the unstable eigenvalues of the dynamic matrix of the plant and the parameters of DoS attacks, under which exponential stability of the closed-loop system can be guaranteed. Our characterization clearly shows the tradeoffs between the communication bandwidth and resilience against DoS. An example is given to illustrate the proposed approach

    Analysis of DoS Attacks at MAC Layer in Mobile Adhoc Networks

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    —Wireless network security has received tremendous attention due to the vulnerabilities exposed in the open communication medium. The most common wireless Medium Access Control (MAC) protocol is IEEE 802.11, which assumes all the nodes in the network are cooperative. However, nodes may purposefully misbehave in order to disrupt network performance, obtain extra bandwidth and conserve resources. These MAC layer misbehaviours can lead to Denial of Service (DoS) attacks which can disrupt the network operation. There is a lack of comprehensive analysis of MAC layer misbehaviour driven DoS attacks for the IEEE 802.11 protocol. This research studied possible MAC layer DoS attack strategies that are driven by the MAC layer malicious/selfish nodes and investigates the performance of the IEEE 802.11 protocol. Such DoS attacks caused by malicious and selfish nodes violating backoff timers associated with the protocol. The experimental and analytical approach evaluates several practical MAC layer backoff value manipulation and the impact of such attacks on the network performance and stability in MANETs. The simulation results show that introducing DoS attacks at MAC layer could significantly affect the network throughput and data packet collision rate. This paper concludes that DoS attacks with selfish/malicious intend can obtain a larger throughput by denying well-behaved nodes to obtain deserved throughput, also DoS attacks with the intend of complete destruction of the network can succee

    A Study on Preventing Node Isolation Attack in OLSR Protocol

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    AbstractA mobile ad hoc network (MANET) is a wireless communication system of continuously self-configuring and infrastructure-less network of mobile devices which can move independently in any direction at any time.Routing protocols is required for message exchange in MANET. The most widely used routing protocol is OLSR (Optimized Link State Routing Protocol). It is efficient in bandwidth utilization and path calculation. But it is vulnerable to many types of attacks. In this paper, we discuss about various methods used to prevent a type of Denial of Service (DoS) attack called the node isolation attack that is capable to compromise OLSR protocol

    Survey on: Software Puzzle for Offsetting DoS Attack

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    A Denial of Service (DoS) attack is a malevolent attempt to make a server or a network resource inaccessible to users, usually by temporarily breaking or suspending the services of a host connected to the Internet. DoS attacks and Distributed DoS (DDoS) attacks attempt to deplete an online service's resource such as network bandwidth, memory and computational power by overwhelming the service with bogus requests. Thus, DoS and DDoS attacks have become a major problem for users of computer systems connected to the Internet. Many state-art of the techniques used for defending the internet from these attacks have been discussed in this paper. After conducting an exhaustive survey on these techniques it has been found that the proposed software puzzle scheme that randomly generates only after a client request is received at the server side gives better performance as compared with previous techniques

    An Approach for Mitigating Denial of Service Attack

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    Distributed Denial of Service (DDoS) attacks are the most common types of cyber-attack on the internet and are rapidly increasing. Denial of service/distributed denial of service attack is an explicit attempt to make a machine or a network resource unavailable to its intended users. Attackers interrupt/suspend services of the host connected to internet temporarily or indefinitely.It involves saturating the target machine with external communication requests such that it cannot either respond to legitimate traffic or responds so slowly as to be rendered effectively unavailable. Two general form of Dos attacks are - those attacks that crashes services (computer attack) and those that flood services (network attack). Flooding DDoS attacks produce adverse effects for critical infrastructure availability, integrity and confidentiality. Current defense approaches cannot efficiently detect and filter out the attack traffic in real time. Based on the assumption that the attacker flows are very aggressive than the legitimate users the proposed work provides sufficient bandwidth to genuine users during flooding DDoS attack.The aim of the project is to implement an approach for mitigating DDoS based on “The Interface Based Rate Limiting (IBRL) algorithm”, used to mitigate the identified DDoS attacks. The implementation is carried out on a simulation tool Omnett++ installed on linux machine. The results are the plots that show that there is considerable increase in the two important and significant measures, response time and packet drop metrics for legitimate users even under DoS and DDoS attacks

    Centralized prevention of denial of service attacks

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    The world has come to depend on the Internet at an increasing rate for communication, e-commerce, and many other essential services. As such, the Internet has become an integral part of the workings of society at large. This has lead to an increased vulnerability to remotely controlled disruption of vital commercial and government operations---with obvious implications. This disruption can be caused by an attack on one or more specific networks which will deny service to legitimate users or an attack on the Internet itself by creating large amounts of spurious traffic (which will deny services to many or all networks). Individual organizations can take steps to protect themselves but this does not solve the problem of an Internet wide attack. This thesis focuses on an analysis of the different types of Denial of Service attacks and suggests an approach to prevent both categories by centralized detection and limitation of excessive packet flows

    Sistem Keamanan Pada Jaringan Wireless Menggunakan Protokol RADIUS

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    Wireless networks require a security system to protect servers from attacks such as Port Scanning and Denial of Service. This research aims to design a wireless network security system using Remote Authentication Dial-In User Service or RADIUS protocol. The research stages include analysis of system requirements, preparation of completeness of system requirements, installation and configuration of the network and RADIUS protocol, detection and prevention testing of attacks, and analysis of test results. The design system used is to implement a single authentication, authorization, and accounting protocol that supports the internal and external networks of the Bahana Taruko Santosa Company. The results of implementing the RADIUS protocol on a wireless network server service can perform a DoS attack filter properly and block unauthorized users from accessing Internet services. Data analysis results show DoS attacks with the type of ICMP Flooding attack and UDP Flooding attack can be blocked with a percentage of 98%. In addition, there is a reduction in unauthenticated user access rights with the result of reducing the amount of bandwidth usage

    Defending Against Denial of Service

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    Civil Society currently faces significant cyber threats. At the top of the list of those threats are Denial of Service (DoS) attacks. The websites of many organizations and individuals have already come under such attacks, and the frequency of those attacks are on the rise. Civil Society frequently does not have the kinds of resources or technical know-how that is available to commercial enterprise and government websites, and often have to exist in adverse political environments where every avenue available, both legal and illegal, is used against them. Therefore, the threat of DoS attacks is unlikely to go away any time soon.A Denial of Service (DoS) attack is any attack that overwhelms a website, causing the content normally provided by that website to no longer be available to regular visitors of the website. Distributed Denial of Service (DDoS) attacks are traffic volumebased attacks originating from a large number of computers, which are usually compromised workstations. These workstations, known as 'zombies', form a widely distributed attack network called a 'botnet'. While many modern Denial of Service attacks are Distributed Denial of Service attacks, this is certainly not true for all denials of service experienced by websites. Therefore, when users first start experiencing difficulty in getting to the website content, it should not be assumed that the site is under a DDoS attack. Many forms of DoS are far easier to implement than DDoS, and so these attacks are still used by parties with malicious intent. Many such DoS attacks are easier to defend against once the mechanism used to cause the denial of service is known. Therefore, it is paramount to do proper analysis of attack traffic when a site becomes unable to perform its normal function. There are two parts to this guide. The first part outlines preparatory steps that can be taken by Civil Society organizations to improve their website's resilience, should it come under attack. However, we do understand that most Civil Society organizations' first introduction to DoS attacks comes when they suddenly find themselves the victim of an attack. The second part of this guide provides a step-by-step process to assist the staff of NGOs to efficiently deal with that stressful situation

    DoS and DDoS Attacks: Defense, Detection and Traceback Mechanisms - A Survey

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    Denial of Service (DoS) or Distributed Denial of Service (DDoS) attacks are typically explicit attempts to exhaust victim2019;s bandwidth or disrupt legitimate users2019; access to services. Traditional architecture of internet is vulnerable to DDoS attacks and it provides an opportunity to an attacker to gain access to a large number of compromised computers by exploiting their vulnerabilities to set up attack networks or Botnets. Once attack network or Botnet has been set up, an attacker invokes a large-scale, coordinated attack against one or more targets. Asa result of the continuous evolution of new attacks and ever-increasing range of vulnerable hosts on the internet, many DDoS attack Detection, Prevention and Traceback mechanisms have been proposed, In this paper, we tend to surveyed different types of attacks and techniques of DDoS attacks and their countermeasures. The significance of this paper is that the coverage of many aspects of countering DDoS attacks including detection, defence and mitigation, traceback approaches, open issues and research challenges
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