For 10 points, name this cryptographic technique in which Peggy asserts the truth of a statement to Victor without conveying any other information.
In the Bellare-Rogaway formulation of these techniques, which employs the random oracle model, it can be completed in a single round because deniability does not exist; in the standard model, one-round protocols are only possible for languages in BPP. Languages for which "Las Vegas", or perfectly-sound versions of this protocol exist are necessarily in RP, as are languages for which there exists a deterministic verifier. This protocol was first applied to the problem of identifying quadratic nonresidues by Goldwasser et al, who showed that one of these exists for every problem in NP. In these protocols, there must exist a polynomial-time non-interactive simulator that is indistinguishable from any (*) cheating strategy. For 10 points, name this cryptographic technique in which Peggy asserts the truth of a statement to Victor without conveying any other information.
In the Bellare-Rogaway formulation of these techniques, which employs the random oracle model, it can be completed in a single round because deniability does not exist; in the standard model, one-round protocols are only possible for languages in BPP.
zero-knowledge proof [or zero-knowledge protocol; prompt on "interactive proof"]