Dear all,
Elvis Dohmatob from Criteo Research is going to give a seminar at Inria on December 10th, at 2pm, room F107.
Feel free to pass the information to anyone interested.
Best,
Julien
Title: Limitations of adversarial robustness: strong No Free Lunch Theorem
Abstract:
This manuscript presents some new results on adversarial robustness in machine
learning, a very important yet largely open problem. We show that if conditioned on
a class label the data distribution satisfies the Talagrand $W_2$ transportation-cost
inequality (for example, this condition is satisfied if the conditional distribution has
density which is log-concave; or the feature space is a compact homogeneous
Riemannian manifold like a sphere, torus, or in fact any compact Lie group; etc.),
any (non-perfect) classifier can be adversarially fooled with high probability once the
perturbations are slightly greater than the natural noise level in the problem. We call
this result The Strong "No Free Lunch'' Theorem as some recent impossibility results
on the subject (Tsipras et al. 2018, Fawzi et al. 2018, Gilmer et al. 2018, etc.) can be
immediately recovered as very particular cases. Our theoretical bounds are
demonstrated on both simulated and real data (MNIST). We also briefly sketch how
these bounds readily extend to distributional robustness. Finally, we conclude the
manuscript with some speculation on possible future research directions.