  Randomized smoothing is considered to be the state-of-the-art provable
defense against adversarial perturbations. However, it heavily exploits the
fact that classifiers map input objects to class probabilities and do not focus
on the ones that learn a metric space in which classification is performed by
computing distances to embeddings of classes prototypes. In this work, we
extend randomized smoothing to few-shot learning models that map inputs to
normalized embeddings. We provide analysis of Lipschitz continuity of such
models and derive robustness certificate against $\ell_2$-bounded perturbations
that may be useful in few-shot learning scenarios. Our theoretical results are
confirmed by experiments on different datasets.
