Yihua Liao, V. Rao Vemuri Mingxing Gong CISC850 Cyber Analytics - - PowerPoint PPT Presentation
Yihua Liao, V. Rao Vemuri Mingxing Gong CISC850 Cyber Analytics - - PowerPoint PPT Presentation
Use of K-Nearest Neighbor classifier for intrusion detection Yihua Liao, V. Rao Vemuri Mingxing Gong CISC850 Cyber Analytics Outline Introduction Methodology Experiments Discussion & Conclusion Outline Introduction
Outline
- Introduction
- Methodology
- Experiments
- Discussion & Conclusion
Outline
- Introduction
- Methodology
- Experiments
- Discussion & Conclusion
Introduction
▪ High false alarm probability or low attack detection accuracy ▪ Two general approaches:
- Misuse detection
- Anomaly detection
▪ Local ordering vs. frequency of system calls
Nearest Neighbour Rule
Consider a two class problem where each sample consists of two measurements (x,y). k = 1 k = 3 Compute the k nearest neighbours and assign the class by majority vote.
Reference: www.robots.ox.ac.uk/~dclaus/cameraloc/samples/nearestneighbour.ppt
Outline
- Introduction
- Methodology
- Experiments
- Discussion & Conclusion
Methodology
- Apply text categorization methods to intrusion detection
Methodology
- Each document is represented by a vector of words
- Weighting approach tf·idf (term frequency – inverse document
frequency)
- The cosine similarity is defined as follows:
Outline
- Introduction
- Methodology
- Experiments
- Discussion & Conclusion
Experiments
- DARPA data
- Cross validation and 50 distinct system calls
KNN classifier algorithm for anomaly detection
KNN classifier performance
- The overall running time of the kNN method is O(N)
- Integrate with signature verification
Anomaly Detection
Frequency Weighting vs. tf·idf Weighting
Frequency Weighting vs. tf·idf Weighting
Outline
- Introduction
- Methodology
- Experiments
- Discussion & Conclusion
Discussion
- kNN Classifier advantages
- Compared tf·idf weighting with the frequency weighting
- Classification cost can be further reduced by only using most
influential system calls
Conclusion
- kNN Classifier is able to effectively detect intrusive program
behavior with low false positive rate
- Further research is in process to investigate the reliability and
scaling properties of the kNN classifier method
Reference
[1] www.robots.ox.ac.uk/~dclaus/cameraloc/samples/nearestneighbour.ppt [2] Yihua Liao, V. Rao Vemuri, ‘Use of K-Nearest Neighbor classifier for intrusion detection’, Computers & Security, Volume 21, Issue 5, 1 October 2002, Pages 439-448