Distributed Verifiers in PCP

TL;DR

This paper introduces a new distributed proof system model called dPCP, expanding on existing models, to verify global network properties through local verifier nodes communicating with a prover.

Contribution

The paper proposes the dPCP model, a novel distributed proof system that differs from LCP and dIP models by its communication structure between verifiers and the prover.

Findings

Introduces the dPCP model for distributed verification.

Analyzes properties and proofs within the dPCP system.

Compares dPCP with existing models like LCP and dIP.

Abstract

Traditional proof systems involve a resource-bounded verifier communicating with a powerful (but untrusted) prover. Distributed verifier proof systems are a new family of proof models that involve a network of verifier nodes communicating with a single independent prover that has access to the complete network structure of the verifiers. The prover is tasked with convincing all verifiers of some global property of the network graph. In addition, each individual verifier may be given some input string they will be required to verify during the course of computation. Verifier nodes are allowed to exchange messaged with nodes a constant distance away, and accept / reject the input after some computation. Because individual nodes are limited to a local view, communication with the prover is potentially necessary to prove global properties about the network graph of nodes, which only the prover has access to. In this system of models, the entire model accepts the input if and only if every individual node has accepted. There are three models in the distributed verifier proof system family: $\mathsf{LCP}$, $\mathsf{dIP}$, and our proposed $\mathsf{dPCP}$, with the fundamental difference between these coming from the type of communication established between the verifiers and the prover. In this paper, we will first go over the past work in the $\mathsf{LCP}$ and $\mathsf{dIP}$ space before showing properties and proofs in our $\mathsf{dPCP}$ system.