The Domain Name System (DNS) domain names to be used in network transactions (email, web requests, etc.) instead of IP addresses. The root of the DNS distributed database is managed by 13 root nameservers. We passively measure the performance of one of them: F.root-servers.net. These measurements show an astounding number of bogus queries: from 60-85% of observed queries were repeated from the ...

Upgrading the software of long-lived distributed systems is difficult. It is not possible to upgrade all the nodes in a system at once, since some nodes may be down and halting the system for an upgrade is unacceptable. This means that different nodes may be running different software versions and yet need to communicate, even though those versions may not be fully compatible. We present a meth...

As an increasing number of businesses and services depend on the Internet, protecting them against DDoS (Distributed Denial of Service) attacks becomes a critical issue. A traceback is used to discover technical information concerning the ingress points, paths, partial paths or sources of a packet or packets causing a problematic network event. The traceback mechanism is a useful tool to identi...

A denial-of-service (DoS) / distributed-denial-of-service (DDoS) attack may result in rapid resource depletion along the attack path. For stepping-stone and masquerading techniques typically used in DoS/DDoS attacks such as internet protocol (IP) or Media Access Control (MAC) address spoofing, tracing the intrusion back to the true attacker becomes a challenging task for network security engine...

A membership service is used to maintain information about which sites are functioning in a distributed system at any given time. Many such services have been defined, with each implementing a unique combination of properties that simplify the construction of higher levels of the system. Despite this wealth of possibilities, however, any given service only realizes one set of properties, which ...

Reduction of Quality (ROQ) attack is one of the Denial of Service (DoS) attacks which affect the MANETs. Instead of refusing the clients from the services completely, these RoQ attacks

Cyber ​​threats have been extraordinary increased in recent years. Cyber ​​attackers, including government agencies or hackers, have made significant advances in the use of various tools for attacking target systems in some countries particularly on Islamic republic of Iran. The complexity of cyber threats and the devastating effects of them on critical systems highlights necessity of cyber thr...

-We are in the era of internet and depend on it for every necessary requirement. It is the tendency of the some human to have destructive approach rather than having constructive approach. Among the abuse and misuse of internet, the distributed denial of service attack (DDOS) is the most hectic one. People have carried out various method of mitigation using the CAPTCHA (Completely Automated Pub...

Recently, Denial of Service(DoS) attacks and Distributed DoS(DDoS) attacks which are stronger form of DoS attacks from plural hosts have become security threats on the Internet. It is important to identify the attack source and to block attack traffic as one of the measures against these attacks. In general, it is difficult to identify them because information about the attack source is falsifi...

Denial-of-Service and Distributed Denial-of-Service is costing the economy world-wide billions of dollars. The economy is the cornerstone of our society and its collapse will certainly change the way in which humanity exists today. The three main goals of computer security are availability, confidentiality and integrity. The focus of this paper is on attacks that compromise the availability of ...