Physical and/or informational devices are used to sense
properties indicative or abnormal operations or activities. Examples
include:
motion sensors in physically secured areas,
explosive detecting sensors in doorways, and
informational sensors in a firewall to detect
unauthorized access attempts.
Complexity: The creation and placement of
sensors is usually a reasonably simple matter, but analyzing sensor data and
acting upon it is a substantially more complex issue.
fc@red.a.net