On interactive proofs with a laconic prover
- Cite this article as:
- Goldreich, O., Vadhan, S. & Wigderson, A. comput. complex. (2002) 11: 1. doi:10.1007/s00037-002-0169-0
We continue the investigation of interactive proofs with bounded communication, as initiated by Goldreich & Håstad (1998). Let L be a language that has an interactive proof in which the prover sends few (say b) bits to the verifier. We prove that the complement $\bar L$ has a constant-round interactive proof of complexity that depends only exponentially on b. This provides the first evidence that for NP-complete languages, we cannot expect interactive provers to be much more “laconic” than the standard NP proof. When the proof system is further restricted (e.g., when b = 1, or when we have perfect completeness), we get significantly better upper bounds on the complexity of $\bar L$.