441Intrusion Detection Systems for (Wireless) Automation Systems
18.2.2 State-of-the-art intruSion detection SySteMS
Different system models for IDS are available; the oldest is the host-based intrusion detection
method. There, an IDS is installed on a host that analyzes the internal state and behavior of a
system. This includes the resource access of programs, trafc targeted to the system, or states of
specic data in the memory of the system.
The whole network trafc is scanned using network intrusion detection systems. Network intru-
sion detection systems analyze the network trafc to nd unauthorized or malicious activities in the
network. In most cases, this is done by a device or computer that is placed in a central position of the ...