Speaker:
Bowei Xi
Purdue University

Abstract: Nowadays more and more data are gathered for detecting and
preventing cyber attacks. Unique to the cyber security
applications, learning models face active adversaries that try to
deceive learning models and avoid being detected. Hence future
datasets and the training data no longer follow the same
distribution. The existence of such adversarial samples
motivates the development of robust and resilient adversarial
learning techniques. Game theory offers a suitable framework to
model the conflict between adversaries and defender. We develop a
game theoretic framework to model the sequential actions of the
adversaries and the defender, allowing players to maximize their
own utilities. For supervised learning tasks, our adversarial
support vector machine has a conservative decision boundary,
whereas our robust deep neural network plays a random strategy
inspired by the mixed equilibrium strategy. One the other hand,
in real practice, labeling the data instances often requires
costly and time-consuming human expertise and becomes a
significant bottleneck. We develop a novel grid based adversarial
clustering algorithm, to understand adversaries' behavior from a
large number of unlabeled instances. Our adversarial clustering
algorithm is able to identify the normal regions inside mixed
clusters, and to draw defensive walls around the center of the normal
objects utilizing game theoretic ideas. Our algorithm also
identifies sub-clusters of adversarial samples and the overlapping areas
within mixed clusters, and identify outliers which may be
potential anomalies.

The weekly security seminar has been held every semester since spring of 1992. We invite personnel at Purdue and visitors from outside to present on topics of particular interest to them in the areas of computer and network security, computer crime investigation, information warfare, information ethics, public policy for computing and security, the computing "underground," and other related topics. More info