Confidential Guardian: Cryptographically Prohibiting the Abuse of Model Abstention

Confidential Guardian: Cryptographically Prohibiting the Abuse of Model Abstention

Cautious predictions — where a machine learning model abstains when uncertain — are crucial for limiting harmful errors in safety-critical applications. In this work, we identify a novel threat: a dishonest institution can exploit these mechanisms to discriminate or unjustly deny services under the guise of uncertainty. We demonstrate the practicality of this threat by introducing an uncertainty-inducing attack called Mirage, which deliberately …