$Proo\varphi$: A ZKP Market Mechanism

TL;DR

This paper introduces a formal market model for zero-knowledge proofs and proposes $Proo\varphi$, an incentive-compatible auction mechanism that addresses practical security challenges in ZKP outsourcing.

Contribution

It presents the first formal ZKP market model and an auction-based mechanism, $Proo\varphi$, with proven incentive compatibility and solutions for practical security issues.

Findings

$Proo\varphi$ is incentive compatible for users and provers.

The mechanism is budget balanced.

System-level designs mitigate security threats like Sybil attacks.

Abstract

Zero-knowledge proofs (ZKPs) are computationally demanding to generate. Their importance for applications like ZK-Rollups has prompted some to outsource ZKP generation to a market of specialized provers. However, existing market designs either do not fit the ZKP setting or lack formal description and analysis. In this work, we propose a formal ZKP market model that captures the interactions between users submitting ZKP tasks and provers competing to generate proofs. Building on this model, we introduce $Proo\varphi$, an auction-based ZKP market mechanism. We prove that $Proo\varphi$ is incentive compatible for users and provers, and budget balanced. We augment $Proo\varphi$ with system-level designs to address the practical challenges of our setting, such as Sybil attacks, misreporting of prover capacity, and collusion. We analyze our system-level designs and show how they can mitigate the various security concerns.