A lightweight argument system with efficient verifier

Abstract

In the Cloud Computing paradigm, users outsource computational tasks from relatively weaker devices to more powerful but untrusted servers. While outsourcing computation provides appealing benefits, natural concerns arise regarding the the correctness of the result. One of the most recent solutions to this problem comes in the form argument systems, which combine commitment protocols and linear probabilistically checkable proofs (PCPs). Although significant efforts have been made to enhance the practicality of argument systems for outsourced computation, the high cost still stymies the successful adoption of argument systems for real-world cloud-based applications. However, we observe that the most burdensome part in a linear PCP protocol - the generation of the queries for circuit tests - is highly redundant. Consequently, in this paper, we propose a novel commitment protocol which provides inherent circuit tests. Based on this commitment protocol, we develop a new light-weight argument system in which an efficient verifier can generate PCP queries for the circuit tests without having to read the circuit and perform weighted summations on the circuit's gate constraints every time a new query is generated.