A Modular Approach to Succinct Arguments for QMA

2026-06-03

AI Summary

This work addresses the construction of succinct, classically verifiable argument systems for QMA without relying on the Learning With Errors (LWE) assumption. To achieve this, the authors propose a modular framework that combines oblivious state preparation (OSP) protocols with collapsing hash functions, yielding the first LWE-free succinct argument system for QMA. Furthermore, they introduce a general-purpose communication compression compiler capable of reducing the communication complexity of any T-round protocol to T·poly(secp). This result substantially broadens the cryptographic foundations underlying succinct arguments for QMA and significantly enhances their efficiency.

Abstract

Succinct argument systems are of central importance to modern crytpography, enabling the efficient verification of computational claims. In the classical setting, Kilian (STOC 92) established that any probabilistically checkable proof for NP can be transformed into a succinct argument system for NP using only collision-resistant hash functions. In the quantum setting, recent works have established the feasibility of (classically-verifiable) succinct arguments for QMA, capturing statements that require *quantum* proofs. However, known constructions all rely on the highly structured assumption of learning with errors (LWE), which stands in stark contrast with the unstructured assumptions that suffice for NP. In this work, we develop a new framework that broadens the cryptographic foundations of succinct arguments for QMA. We assume the existence of (i) an oblivious state preparation (OSP) protocol, which in turn can be constructed from *plain* trapdoor claw-free functions, and (ii) collapsing hash functions, the quantum analogue of collision-resistance. In particular, we obtain the first succinct, classically-verifiable argument system for QMA which does not rely on the hardness of LWE. Our construction proceeds in two steps. First, we design a *round-efficient* classically-verifiable argument system for QMA based only on the assumption of OSP. Second, we introduce a *generalized communication compression compiler*, which, assuming collapsing hash functions, transforms any $T$-round interactive protocol into one in which the communication size is bounded by $T \cdot \poly(\secp)$ for some fixed $\poly$ independent of the original size of each message. Our compiler extends a quantum rigidity-based communication compression technique of Zhang (QCrypt 25), and may be of independent interest.

Problem

• succinct arguments
• QMA
• LWE
• classically-verifiable
• quantum cryptography

Innovation

• succinct arguments
• QMA
• oblivious state preparation
• collapsing hash functions
• communication compression