Paper 2026/302 Original: eprint.iacr.org/2026/302 ↗

Non Interactive MPC, (Quantumly) Revisited

Abstract

Classical non-interactive secure computation, despite being extensively studied, suffers from an inherent barrier: adversaries can learn the entire residual function via resetting attacks. We investigate whether quantum resources can circumvent this barrier and restrict adversarial leakage. Our results are as follows: 1. $\textbf{Definitions}$: We introduce new security definitions for the one-message MPC and 2PC settings that restrict the amount of adversarial leakage compared to prior classical definitions. 2. $\textbf{MPC}$: There exist information-theoretically secure one-message multi-party computation protocols in the oracle model in both the quantum pre-processing and classical pre-processing settings. 3. $\textbf{2PC}$: There exist semi-honest secure one-message two-party computation for (randomized) pseudorandom functionalities in the plain model based on LWE and maliciously secure one-message two-party computation for (randomized) constrained functionalities in the CRS model based on iO. Prior work by [Gupte, Liu, Raizes, Roberts and, Vaikuntanathan STOC 2025] achieved semi-honest security based on iO. Our results demonstrate the power of quantum information to circumvent barriers in classical secure computation.