  Lipschitz Bound Estimation is an effective method of regularizing deep neural
networks to make them robust against adversarial attacks. This is useful in a
variety of applications ranging from reinforcement learning to autonomous
systems. In this paper, we highlight the significant gap in obtaining a
non-trivial Lipschitz bound certificate for Convolutional Neural Networks
(CNNs) and empirically support it with extensive graphical analysis. We also
show that unrolling Convolutional layers or Toeplitz matrices can be employed
to convert Convolutional Neural Networks (CNNs) to a Fully Connected Network.
Further, we propose a simple algorithm to show the existing 20x-50x gap in a
particular data distribution between the actual lipschitz constant and the
obtained tight bound. We also ran sets of thorough experiments on various
network architectures and benchmark them on datasets like MNIST and CIFAR-10.
All these proposals are supported by extensive testing, graphs, histograms and
comparative analysis.
