
18 The State of the Art in Intrusion Prevention and Detection
1.6.2.1 Histogramming
It is a model that involves counting the frequency of occurrence of different data instances and then
compares the test instance with each of the histogram categories to test whether it belongs to any
of them.
Sheng et al. [52] proposed a histogram-based technique for outlier detection to reduce the com-
munication cost for data collection applications of sensor networks. Rather than collecting all the
data in one location for centralized processing, they propose collecting hints about the data distri-
bution and using the hints to lter out unnecessary data a