Interactive PCP

A central line of research in the area of PCPs is devoted to constructing short PCPs. In this paper, we show that if we allow an additional interactive verification phase, with very low communication complexity, then for some NP languages, one can construct PCPs that are significantly shorter than the known PCPs (without the additional interactive phase) for these languages. We give many cryptographical applications and motivations for our results and for the study of the new model in general. More specifically, we study a new model of proofs: interactive-PCP. Roughly speaking, an interactive-PCP (say, for the membership x ∈ L) is a proof-string that can be verified by reading only one of its bits, with the help of an interactive-proof with very small communication complexity. We show that for membership in some NP languages L, there are interactive-PCPs that are significantly shorter than the known (non-interactive) PCPs for these languages. Our main result is that for any con...

• Type: Journal
• Year: 2007
• Where: ECCC
• Authors: Yael Tauman Kalai, Ran Raz
• Keywords: Communication Complexity, ECCC 2007, Low Communication Complexity, NP Languages