A New Passive NATted Hosts Counting Method Based on Hough Transform.

To solve the problem of NATted (Network Address Translator, NAT) hosts counting in network security, a new method based on Hough transform is proposed. By exploiting the linear relation between TCP timestamp and received time in the packets, the problem is transformed to counting lines in the coordinate graph. Hough transform is introduced to detect lines in the graph. To get more precise result, zooming in the graph iteratively is used in the algorithm. Compared with existing algorithms, the proposed method can solve the problem of choosing initial clusters, and improve the detection accuracy with intersected or short distance timestamp sequence. Experiment results show that the algorithm based on Hough transform can detect the number of NATted hosts precisely which outperforms existing methods. [ABSTRACT FROM AUTHOR]