With machine learning models being used for more sensitive applications, we
rely on interpretability methods to prove that no discriminating attributes
were used for classification. A potential concern is the so-called
"fair-washing" - manipulating a model such that the features used in reality
are hidden and more innocuous features are shown to be important instead.
In our work we present an effective defence against such adversarial attacks
on neural networks. By a simple aggregation of multiple explanation methods,
the network becomes robust against manipulation. This holds even when the
attacker has exact knowledge of the model weights and the explanation methods
used.