New Perspectives on Zero-Knowledge Multi-Prover Interactive Proofs

In multi-prover interactive proofs (MIPs), the verifier can provide non-local resources for the provers intrinsically. In most cases, this is undesirable. Existing proofs of soundness do not account for the verifier's non-local potential. We show that this may be a problem for many MIPs. We provide a solution by constructing a generalization of the MIP model, of which standard MIPs are a special case. This new model accounts for both the prover and the verifier's non-local correlations. A new property of multi-prover zero-knowledge naturally emerges as a result.