Consider a challenge-response protocol where the probability of a correct response is at least α for a legitimate user and at most β < α for an attacker. One example is a CAP...
Russell Impagliazzo, Ragesh Jaiswal, Valentine Kab...
Abstract. We consider weakly-verifiable puzzles which are challengeresponse puzzles such that the responder may not be able to verify for itself whether it answered the challenge ...