  Self-testing is the task where spatially separated Alice and Bob cooperate to
deduce the inner workings of untrusted quantum devices by interacting with them
in a classical manner. We examine the task above where Alice and Bob do not
trust each other which we call adversarial self-testing. We show that
adversarial self-testing implies secure sampling -- a task that we introduce
where mistrustful Alice and Bob wish to sample from a joint probability
distribution with the guarantee that an honest party's marginal is not biased.
By extending impossibility results in two-party quantum cryptography, we give a
simple proof that both of these tasks are impossible in all but trivial
settings.
