Verifiable Random Sampling

2026-07-29

AI Summary

Traditional verifiable random functions (VRFs) produce fixed outputs once their public keys are published, lacking sample freshness and thus remaining vulnerable to collusion and exhaustive-search attacks. This work proposes a new paradigm—verifiable random sampling (VRS)—and provides the first formal definition of this concept, unifying sample freshness and public verifiability within a rigorous cryptographic framework. The construction achieves composable security and integrates feasible random circuit sampling (RCS) with multi-party protocols to generate samples that statistically approximate a target distribution while remaining publicly verifiable. By doing so, the scheme effectively mitigates precomputation and selective exploitation attacks, simultaneously ensuring unpredictability, freshness, and verifiability in a coherent and robust manner.

Abstract

Verifiable random functions (VRF) underpin a wide range of applications that require publicly verifiable evaluations of a pseudorandom function on a given input. However, once the public key is published, the induced function is fixed and is a deterministic function of the input. This determinism can enable collusion and grinding-style attacks in which adversaries precompute and selectively exploit favorable input-output pairs. To address these limitations, we introduce the formal notion of verifiable random sampling (VRS). We propose a concrete VRS construction based on random quantum circuit sampling (RCS) executable on today's quantum computing devices. VRS supports multiparty protocols in which the verifier's final output is a sample that is statistically close to a specified target distribution, while remaining publicly verifiable. We model the construction and prove its security within the constructive cryptography (CC) framework, thereby ensuring composability with other cryptographic protocols. Overall, our results provide a mechanism for verifiable random sampling that simultaneously guarantees sample freshness and public verifiability, enabling applications that require unpredictable, fresh randomness while preserving fairness through public verifiability.

Problem

• verifiable random functions
• collusion attacks
• grinding attacks
• randomness freshness
• public verifiability

Innovation

• Verifiable Random Sampling
• Random Quantum Circuit Sampling
• Constructive Cryptography
• Public Verifiability
• Sample Freshness