DENIAL OF SERVICE ATTACKS

Denial-of-Service Attacks

Denial-of-Service Attacks

Abstract

Denial of service attacks used by an individual to destroy, stop or degrade your computer or network resource. The aim of such attacks is to flood the communication ports and memory buffer target site to prevent the receipt of legitimate messages, and the legitimate demands of the service connection. Denial of service attacks can be used to reduce the server, the hacker wants to cheat. For example, an attacker may try to fake bank for PIN-code or credit card numbers.

Introduction

Problem Statement

When it comes to computer science purest meaning of the phrase "denial of service" was, as it sounds, denying services or access to those have not been approved. Today, a denial of service takes on a whole new meaning, instead of keeping your computer secure is a tool used to cause destruction. DoS (Denial of Service) is an attack in which an internet resource, network, or computer unusable (Ryan, 2007). This attack is carried out by sending an unmanageable amount of data that causes an overload of the system, and sometimes collapse. Focused system can be anything from a singular computer (though not very useful to attack), the IRC servers, email services or web sites. With or method of attack may vary DoS attack is not particular, but the result is always the same. Victims of slowing down, some might say artificially, and the resource, either completely absent or without speed to achieve something within a reasonable time (Ptacek, 2007).

Objective

The objective of this paper is to address the following:

The security risks associated with the DOS, which the bank and customers currently face in the network settings.

Explanation of why these security risks exist.

Literature Review

Node-based attack defenses

In node-based attacks, the imbalance between the amount of resources needed to make a request and the amount of resources needed to satisfy this request creates a cost-effective DoS attack opportunity. By sending a cheap illegitimate request, an attacker can hold a quantifiable amount of resources. Launching a large amount of such requests can exhaust the finite server resources. Some mechanisms were developed to defend against such attacks. Resource pricing (Ryan, 2007) assigns a dynamic cost to each resource based on the system load. This cost has to be dispensed from the requesting client before the resource is allocated. Client puzzles (Ptacek, 2007) is a special case of such a pricing mechanism, where the client has to solve a cryptographic problem with varying complexity before the server allocates resources to the request and starts servicing it. Both of these techniques can be implemented transparently to the server application, either as a gateway or as a middleware layer. The main disadvantage is the requirement of special client software.

The lack of resource management facilities in current widely-deployed operating systems is another cause of the node-based DoS attacks. The ability to account for resources allocated to each client according to negotiated contracts, detect contract violations and recover misused resources is a design target of the Scout operating system (Mell, ...