Date Added: Jul 2009
Intrusion-detection systems endeavor at detecting attacks against networks or, in general, against information systems. Undeniably, it is convoluted to provide provably secure network and to maintain them in such a secure state during their lifetime and utilization. Sometimes, legacy or operational constraints do not even allow the definition of a fully secure network. Therefore, intrusion detection systems have the task of monitoring the usage of such systems to detect any apparition of insecure states. They detect attempts and active misuse either by legitimate users of the systems or by external parties to abuse their privileges or exploit security vulnerabilities.