Complexity attacks.

Abstract- Computer security is very important for any organization that maintains sensitive assets electronically. This is stressed in the statistics collected by the Computer Security Institute and FBI through their annual surveys. Hence, DOS is a very important problem that needs to be dealt with seriously, DOS attacks are of two types: flooding attacks and logic attacks. When an attack has impact on a system parameter, then the parameter can be used as an attack detection metric. In this paper, we qualitatively and quantitatively analyze the impact of DOS attacks on three simple system parameters- request arrival rate, queue-growth-rate, and response time. The importance of this analysis lies in the fact that we don't need to observe the system for a long time to understand the comparative system degradations that may happen under certain types of attacks