Date Added: Oct 2009
Security is an important factor of the Network Protection. Zero-day attacks, new (anamolous) attacks exploiting previously unknown system vulnerabilities, have become potentially serious threats to the very existence of the Network itself. Defending against them is no easy task. However, having identified "Degree of system knowledge" as one difference between legitimate and illegitimate users, theorists have drawn on information theory as a basis for intrusion detection. Intrusion Detection Systems (IDS) have become one of the most common countermeasures in the network security arsenal.