Denial of Service Attacks

In 2006, 100,000 servers were broken down just within 10 minutes . Those were the victims of some Denial-of-Service attacks. This news and knowing that some of those victims were so well-known companies like Hotmail and Amazon, indicate the significance of this kind of threats and attacks. "In a DoS attack, a malicious client (called the attacker) performs operations designed to partially or completely prevent legitimate clients from gaining service form a server (called the victim)" . DoS attacks can be categorized in two main classes: logic attacks and flooding attacks. In flooding attacks, which are discussed in this paper, the resources of the victim server are consumed by sending a big number of requests to it in order to make it unable to provide appropriate services to legitimate clients.

Data security plays a crucial role in healthcare monitoring systems, since critical patient information is transacted over the Internet, especially through wireless devices, wireless routes such as optical wireless channels, or optical transport networks related to optical fibers. Many hospitals are acquiring their own metro dark fiber networks for collaborating with other institutes as a way to maximize their capacity to meet patient needs, as sharing scarce and expensive assets, such as scanners, allows them to optimize their efficiency. The primary goal of this article is to develop of an attack detection model suitable for healthcare monitoring systems that uses internet protocol (IP) virtual private networks (VPNs) over optical transport networks. To this end, this article presents the vulnerabilities in healthcare monitoring system networks, which employ VPNs over optical transport layer architecture. Furthermore, a multilayer network architecture for closer integration of the...

Despite a plethora of research in the area, none of the mechanisms proposed so far for Denial-of-Service (DoS) mitigation has been widely deployed. We argue in this paper that these deployment difficulties are primarily due to economic inefficiency, rather than to technical shortcomings of the proposed DoS-resilient technologies. We identify economic phenomena, negative externality---the benefit derived from adopting a technology depends on the action of others---and economic incentive misalignment---the party who suffers from an economic loss is different from the party who is in the best position to prevent that loss---as the main stumbling blocks of adoption. Our main contribution is a novel DoS mitigation architecture, Burrows, with an economic incentive realignment property. Burrows is obtained by re-factoring existing key DoS mitigation technologies, and can increase the "social welfare," i.e., economic benefit, of the entire Internet community---both infrastructure ...

Denial of Service (DoS) attacks constitute one of the major threats and among the hardest security problems in todayÕs Internet. Of particular concern are Distributed Denial of Service (DDoS) attacks, whose impact can be proportionally severe. With little or no advance warning, a DDoS attack can easily exhaust the computing and communication resources of its victim within a short period of time. Because of the seriousness of the problem many defense mechanisms have been proposed to combat these attacks. This paper presents a structural approach to the DDoS problem by developing a classification of DDoS attacks and DDoS defense mechanisms. Furthermore, important features of each attack and defense system category are described and advantages and disadvantages of each proposed scheme are outlined. The goal of the paper is to place some order into the existing attack and defense mechanisms, so that a better understanding of DDoS attacks can be achieved and subsequently more efficient and effective algorithms, techniques and procedures to combat these attacks may be developed.

Cognitive radio technologies have emerged as a platform to solve the problem of spectrum scarcity for wireless applications since cognitive radios have the potential to utilize the idle licensed spectrum bands in an intelligent way without interfering with other licensed devices. However, most of the proposed protocols for opportunistic usage of the licensed spectrum bands assume that the participants involved in the protocols are honest and that there are no malicious adversaries that will attack the network. Using two examples, we demonstrate that in the presence of a malicious adversary the systems designed making these assumptions will fail to fulfill their goals of minimal disruption of the primary users and efficient utilization of the unused spectrum. We also briefly discuss some security design goals of the future cognitive DSA networks.

The 4-way Wi-Fi handshake is used to negotiate fresh pairwise keys, and authenticates both the client and Access Point (AP). We analyze this handshake, and discover several new denial-of-service (DoS) attacks against it. Interestingly, our attacks work even if Management Frame Protection (MFP) is enabled. The first attack abuses the observation that messages in the 4-way handshake undergo link-layer encryption once the pairwise key is installed. More precisely, when message 4 of the handshake is dropped, the handshake times out. The second attack is similar to the second one, but induces the AP into sending the first message 4 with link-layer encryption. Again, this causes the handshake to time out. In the third attack, an adversary waits until the victim completes the 4-way handshake. Then she initiates a rekey by injecting a malformed 4-way handshake messages, causing several implementations to disconnect the client from the network. Finally, we propose countermeasures against our discovered attacks.

Denial of Service attacks constitute one of the greatest problem in network security. Monitoring traffic is one of the main techniques used in order to find out the existence of possible outliers in the traffic patterns. In this paper, we propose an approach that detects Denial of Service attacks using Emergent Self-Organizing Maps. The approach is based on classifying "normal" traffic against "abnormal" traffic in the sense of Denial of Service attacks. The approach permits the automatic classification of events that are contained in logs and visualization of network traffic. Extensive simulations show the effectiveness of this approach compared to previously proposed approaches regarding false alarms and detection probabilities.

We describe Just Fast Keying (JFK), a new key-exchange protocol, primarily designed for use in the IP security architecture. It is simple, efficient, and secure; we sketch a proof of the latter property. JFK also has a number of novel engineering parameters that permit a variety of tradeoffs, most notably the ability to balance the need for perfect forward secrecy against susceptibility to denial-of-service attacks.

Data security plays a crucial role in healthcare monitoring systems, since critical patient information is transacted over the Internet, especially through wireless devices, wireless routes such as optical wireless channels, or optical transport networks related to optical fibers. Many hospitals are acquiring their own metro dark fiber networks for collaborating with other institutes as a way to maximize their capacity to meet patient needs, as sharing scarce and expensive assets, such as scanners, allows them to optimize their efficiency. The primary goal of this article is to develop of an attack detection model suitable for healthcare monitoring systems that uses internet protocol (IP) virtual private networks (VPNs) over optical transport networks. To this end, this article presents the vulnerabilities in healthcare monitoring system networks, which employ VPNs over optical transport layer architecture. Furthermore, a multilayer network architecture for closer integration of the...

Sleep deprivation attacks are a form of denial of service attack whereby an attacker renders a pervasive computing device inoperable by draining the battery more quickly than it would be drained under normal usage. We describe three main methods for an attacker to drain the battery: (1) Service request power attacks, where repeated requests are made to the victim for services, typically over a network-even if the service is not provided the victim must expend energy deciding whether or not to honor the request; (2) benign power attacks, where the victim is made to execute a valid but energy-hungry task repeatedly, and (3) malignant power attacks, where the attacker modifies or creates an executable to make the system consume more energy than it would otherwise. Our initial results demonstrate the increased power consumption due to these attacks, which we believe are the first real examples of these attacks to appear in the literature. We also propose a power-secure architecture to thwart these power attacks by employing multi-level authentication and energy signatures.

Denial of Service (DOS) attacks are an immense threat to lntemet sites and among the hardest security problems in today's Intemet. Of particular concernbecause of their potential impactare the Distributed Denial of Service (DDoS) attacks. With little or no advance warning a DDoS attack can easily exhaust the computing and communication resources of its victim within a short period of time. This paper presents the problem of DDoS attacks and develops a classification of DDoS defense systems. Important features of each attack and defense system category are described and advantages and disadvantages of each proposed scheme are outlined. The goal of the paper is to place some order into the existing attack and defense mechanisms, so that a better understanding of DDoS attacks can be achieved and more efficient defense mechanisms and techniques can he devised.

ABSTRACT Denial of Service (DoS) attacks evolved and consolidated as severe security threats to network servers, not only for Internet Service Providers but also for governments. Earlier DoS attacks involved high-bandwidth flood-based approaches exploiting vulnerabilities of networking and transport protocol layers. Subsequently, Distributed DoS attacks have been introduced amplifying not only the overall attack bandwidth but also the attack source, thus eluding simple counter measures based on source filtering. Current low bit-rate approaches, instead, exploit vulnerabilities of application layer protocols to accomplish DoS or DDoS attacks. Slow DoS Attacks like, e.g., slowloris are particularly dangerous because they can bring down a well equipped server using small attacker’s bandwidth, hence they can effectively run on low performance hosts, such as routers, game consoles, or mobile phones. In this paper, we study Slow DoS Attacks, analyzing in detail the current threats and presenting a proper definition and categorization for such attacks. Hopefully, our work will provide a useful framework for the study of this field, for the analysis of network vulnerabilities, and for the proposal of innovative Intrusion Detection methodologies.

Countermeasures against denial of service attacks and node misbehaviour are mandatory requirements in MANET. Essential network operations assuring basic connectivity can be heavily jeopardized by nodes that do not properly execute their share of the network operations. We suggest a security mechanism based on a collaborative monitoring technique that prevents active and passive denial of service attacks by enforcing node cooperation. This mechanism can be smoothly extended to basic network functions ...

Networks are prone to security attacks, and wireless infrastructure network is more vulnerable. The number of people preferring Wireless networks compared to the wired network has seen an expansion of user base owing to the fast and easy installation of wireless infrastructure. Security issues also increases proportionally as the number of users increases. One of the major security issues witnessed in wireless networks is denial-of service (DoS) attack. A denial-of service (DoS) attack can be defined as an attempt to make the network resource unavailable to its intended users, which may be to temporarily interrupt or suspend services of a host connected to the Internet. Therefore it is imperative to understand the extent of, the effect of denial of service attack on normal network performance. In this paper the effect on network performance due to Denial of Service attack is evaluated by measuring the throughput, number of packets received and the number of packets lost and then comparing it with a network which is not under attack.

Countermeasures against node misbehavior and selfishness are mandatory requirements in mobile ad hoc networks. Selfishness that causes lack of node activity cannot be solved by classical security means that aim at verifying the correctness and integrity of an operation. In this paper we outline an original security mechanism (CORE) based on reputation that is used to enforce cooperation among the nodes of a MANET. We then investigate on its robustness using an original approach: we use game theory to model ...

We consider the local broadcasting problem in the SINR model, which is a basic primitive for gathering initial information among n wireless nodes. Assuming that nodes can measure received power, we achieve an essentially optimal constant approximate algorithm (with a log 2 n additive term). This improves upon the previous best O(log n)-approximate algorithm. Without power measurement, our algorithm achieves O(log n)-approximation, matching the previous best result, but with a simpler approach that works under harsher conditions, such as arbitrary node failures. We give complementary lower bounds under reasonable assumptions.

Denial of Service (DoS) attacks constitute one of the major threats and among the hardest security problems in todayÕs Internet. Of particular concern are Distributed Denial of Service (DDoS) attacks, whose impact can be proportionally severe. With little or no advance warning, a DDoS attack can easily exhaust the computing and communication resources of its victim within a short period of time. Because of the seriousness of the problem many defense mechanisms have been proposed to combat these attacks. This paper presents a structural approach to the DDoS problem by developing a classification of DDoS attacks and DDoS defense mechanisms. Furthermore, important features of each attack and defense system category are described and advantages and disadvantages of each proposed scheme are outlined. The goal of the paper is to place some order into the existing attack and defense mechanisms, so that a better understanding of DDoS attacks can be achieved and subsequently more efficient and effective algorithms, techniques and procedures to combat these attacks may be developed.

Serverless distributed computing has received significant attention from both the industry and the research community. Among the most popular applications are the wide-area network file systems, exemplified by CFS, Farsite, and OceanStore. These file systems store files on a large collection of untrusted nodes that form an overlay network. They use cryptographic techniques to maintain file confidentiality and integrity from malicious nodes. Unfortunately, cryptographic techniques cannot protect a file holder from a denial-of-service (DoS) attack or a host compromise attack. Hence, most of these distributed file systems are vulnerable to targeted file attacks, wherein an adversary attempts to attack a small (chosen) set of files by attacking the nodes that host them. This paper presents LocationGuard-a location hiding technique for securing overlay file storage systems from targeted file attacks. LocationGuard has three essential components: 1) location key, consisting of a random bit string (e.g., 128 bits) that serves as the key to the location of a file, 2) routing guard, a secure algorithm that protects accesses to a file in the overlay network given its location key such that neither its key nor its location is revealed to an adversary, and 3) a set of location inference guards, which refer to an extensible component of the LocationGuard. Our experimental results quantify the overhead of employing LocationGuard and demonstrate its effectiveness against DoS attacks, host compromise attacks, and various location inference attacks.

Recently there has been a great need to provide an adequate security level in Cloud Environments, as they are vulnerable to various attacks. Malicious behaviors such as Denial of Service attacks, especially when targeting large-scale data management systems, cannot be detected by typical authentication mechanisms and are responsible for drastically degrading the overall performance of such systems. In this paper we propose a generic security management framework allowing providers of Cloud data management systems to define and enforce complex security policies. This security framework is designed to detect and stop a large array of attacks defined through an expressive policy description language and to be easily interfaced with various data management systems. We show that we can efficiently protect a data storage system, by evaluating our security framework on top of the BlobSeer data management platform. We evaluate the benefits of preventing a DoS attack targeted towards BlobSeer through experiments performed on the Grid'5000 testbed.

While the DETER testbed provides a safe environment and basic tools for security experimentation, researchers face a significant challenge in assembling the testbed pieces and tools into realistic and complete experimental scenarios. In this paper, we describe our work on developing a set of sampled and comprehensive benchmark scenarios, and a workbench for experiments involving denial-of-service (DoS) attacks. The benchmark scenarios are developed by sampling features of attacks, legitimate traffic and topologies from the real Internet. We have also developed a measure of DoS impact on network services to evaluate the severity of an attack and the effectiveness of a proposed defense.

Sleep deprivation attacks are a form of denial of service attack whereby an attacker renders a pervasive computing device inoperable by draining the battery more quickly than it would be drained under normal usage. We describe three main methods for an attacker to drain the battery: (1) Service request power attacks, where repeated requests are made to the victim for services, typically over a network-even if the service is not provided the victim must expend energy deciding whether or not to honor the request; (2) benign power attacks, where the victim is made to execute a valid but energy-hungry task repeatedly, and (3) malignant power attacks, where the attacker modifies or creates an executable to make the system consume more energy than it would otherwise. Our initial results demonstrate the increased power consumption due to these attacks, which we believe are the first real examples of these attacks to appear in the literature. We also propose a power-secure architecture to thwart these power attacks by employing multi-level authentication and energy signatures.

In this paper we describe the model used for the NewsWire collaborative content delivery system. The system builds on the robustness and scalability of Astrolabe to weave a peer-to-peer infrastructure for real-time delivery of news items. The goal of the system is to deliver news updates to hundreds of thousands of subscribers within tens of seconds of the moment of publishing. The system significantly reduces the compute and network load at the publishers and guarantees delivery even in the face of publisher overload or denial of service attacks.

Data security plays a crucial role in healthcare monitoring systems, since critical patient information is transacted over the Internet, especially through wireless devices, wireless routes such as optical wireless channels, or optical transport networks related to optical fibers. Many hospitals are acquiring their own metro dark fiber networks for collaborating with other institutes as a way to maximize their capacity to meet patient needs, as sharing scarce and expensive assets, such as scanners, allows them to optimize their efficiency. The primary goal of this article is to develop of an attack detection model suitable for healthcare monitoring systems that uses internet protocol (IP) virtual private networks (VPNs) over optical transport networks. To this end, this article presents the vulnerabilities in healthcare monitoring system networks, which employ VPNs over optical transport layer architecture. Furthermore, a multilayer network architecture for closer integration of the...

Countermeasures against node misbehavior and selfishness are mandatory requirements in mobile ad hocnetworks. Selfishness that causes lack of node activity cannot be solved by classical security means that aim at verifyingthe correctness and integrity of an operation. In this paper we outline an original security mechanism (CORE) based onreputation that is used to enforce cooperation among the nodes of a MANET. We then investigate on its robustnessusing an original approach: we use game theory to model the interactions ...

Data security plays a crucial role in healthcare monitoring systems, since critical patient information is transacted over the Internet, especially through wireless devices, wireless routes such as optical wireless channels, or optical transport networks related to optical fibers. Many hospitals are acquiring their own metro dark fiber networks for collaborating with other institutes as a way to maximize their capacity to meet patient needs, as sharing scarce and expensive assets, such as scanners, allows them to optimize their efficiency. The primary goal of this article is to develop of an attack detection model suitable for healthcare monitoring systems that uses internet protocol (IP) virtual private networks (VPNs) over optical transport networks. To this end, this article presents the vulnerabilities in healthcare monitoring system networks, which employ VPNs over optical transport layer architecture. Furthermore, a multilayer network architecture for closer integration of the...

Data security plays a crucial role in healthcare monitoring systems, since critical patient information is transacted over the Internet, especially through wireless devices, wireless routes such as optical wireless channels, or optical transport networks related to optical fibers. Many hospitals are acquiring their own metro dark fiber networks for collaborating with other institutes as a way to maximize their capacity to meet patient needs, as sharing scarce and expensive assets, such as scanners, allows them to optimize their efficiency. The primary goal of this article is to develop of an attack detection model suitable for healthcare monitoring systems that uses internet protocol (IP) virtual private networks (VPNs) over optical transport networks. To this end, this article presents the vulnerabilities in healthcare monitoring system networks, which employ VPNs over optical transport layer architecture. Furthermore, a multilayer network architecture for closer integration of the IP and optical layers is proposed, and an application for detecting DoS attacks is introduced. The proposed application is a lightweight implementation that could be applied and installed into various remote healthcare control devices with limited processing and memory resources. Finally, an analytical and focused approach correlated to attack detection is proposed, which can also serve as a tutorial oriented towards even nonprofessionals for practical and learning purposes.

This paper proposes a traffic anomaly detector, operated in postmortem and in real-time, by passively monitoring packet headers of traffic. The frequent attacks on network infrastructure, using various forms of denial of service attacks, have led to an increased need for developing techniques for analyzing network traffic. If efficient analysis tools were available, it could become possible to detect the attacks, anomalies and to take action to contain the attacks appropriately before they have had time to propagate across the network. In this paper, we suggest a technique for traffic anomaly detection based on analyzing correlation of destination IP addresses in outgoing traffic at an egress router. This address correlation data are transformed using discrete wavelet transform for effective detection of anomalies through statistical analysis. Results from trace-driven evaluation suggest that proposed approach could provide an effective means of detecting anomalies close to the source. We also present a multidimensional indicator using the correlation of port numbers and the number of flows as a means of detecting anomalies.

Recently, several papers have studied the possibility of shrinking buffer sizes in Internet core routers to just a few dozen packets under certain constraints. If proven right, these results can open doors to building all-optical routers, since a major bottleneck in building such routers is the lack of large optical memories. However, reducing buffer sizes might pose new security risks: it is much easier to fill up tiny buffers, and thus organizing Denial of Service (DoS) attacks seems easier in a network with tiny buffers. To the best of our knowledge, such risks have not been studied before; all the focus has been on performance issues such as throughput, drop rate, and flow completion times. In this paper, we study DoS attacks in the context of networks with tiny buffers. We show that even though it is easier to fill up tiny buffers, synchronizing flows is more difficult. Therefore to reduce the network throughput, the attacker needs to utilize attacks with high packet injection rates. Since such attacks are easily detected, we conclude that DoS attacks are in fact more difficult in networks with tiny buffers.

Intrusion prevention systems (IPSs) have become widely recognized as a powerful tool and an important element of IT security safeguards. Essential to every network intrusion prevention system is the ability to search through packets and identify patterns that match known attacks. Resource- and time-efficient string matching algorithms are therefore important for identifying these packets at the line rate. Recently these