What are the primary goals of intrusion detection systems? (Select all that apply.)

A.
Accountability

B.
Availability

C.
Response

D.
All of the choices

Explanation:
Although there are many goals associated with security mechanisms in general, there are
two overarching goals usually stated for intrusion detection systems.
Accountability is the capability to link a given activity or event back to the party
responsible for initiating it. This is essential in cases where one wishes to bring
criminal charges against an attacker. The goal statement associated with accountability
is: “I can deal with security attacks that occur on my systems as long as I know who

did it (and where to find them.)” Accountability is difficult in TCP/IP networks, where
the protocols allow attackers to forge the identity of source addresses or other source
identifiers. It is also extremely difficult to enforce accountability in any system
that employs weak identification and authentication mechanisms.
Response is the capability to recognize a given activity or event as an attack and then
taking action to block or otherwise affect its ultimate goal. The goal statement
associated with response is “I don’t care who attacks my system as long as I can
recognize that the attack is taking place and block it.” Note that the requirements of
detection are quite different for response than for accountability.