This document summarizes and characterizes trends in data mining techniques for intrusion detection systems. It discusses how data mining can help address limitations in traditional intrusion detection by identifying anomalies, false alarms, and patterns across data. The document then characterizes several data mining techniques that have been applied for intrusion detection, including feature selection, statistical techniques, machine learning approaches like classification and clustering, and specific algorithms like decision trees, genetic algorithms, fuzzy logic, neural networks, and support vector machines.