Post-Quantum Secure Decentralized Random Number Generation Protocol with Two Rounds of Communication in the Standard Model

2025-05-12

AI Summary

Existing decentralized random number generation (DRNG) protocols either lack post-quantum security or rely on the random oracle model (ROM), while suffering from high communication round complexity and limited fault tolerance. This paper proposes the first provably secure, post-quantum DRNG protocol in the standard model. Our construction leverages lattice-based publicly verifiable secret sharing (PVSS), integrated with threshold encryption and zero-knowledge proofs, to generate publicly verifiable randomness in only two communication rounds. It tolerates up to $t < n/2$ malicious parties among $n$ participants, achieving strong robustness and efficiency. To the best of our knowledge, this is the first DRNG protocol that simultaneously satisfies four key properties: (i) post-quantum security, (ii) standard-model provable security (eliminating ROM assumptions), (iii) two-round communication complexity, and (iv) optimal Byzantine fault tolerance. The scheme thus provides a cryptographically sound foundation for randomness in blockchain and distributed systems.

Technology Category

• Machine Learning: Quantum Machine Learning
• Reasoning under Uncertainty: Stochastic Optimization
• Search and Optimization: Distributed Search

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Responsible Web: Data and user privacy-enhancing technologies for the Web
• Search and Retrieval-Augmented AI: Retrieval-Augmented Generation (RAG) and multi-modal RAG

Abstract

Randomness plays a vital role in numerous applications, including simulation, cryptography, distributed systems, and gaming. Consequently, extensive research has been conducted to generate randomness. One such method is to design a decentralized random number generator (DRNG), a protocol that enables multiple participants to collaboratively generate random outputs that must be publicly verifiable. However, existing DRNGs are either not secure against quantum computers or depend on the random oracle model (ROM) to achieve security. In this paper, we design a DRNG based on lattice-based publicly verifiable secret sharing (PVSS) that is post-quantum secure and proven secure in the standard model. Additionally, our DRNG requires only two rounds of communication to generate a single (pseudo)random value and can tolerate up to any t<n/2 dishonest participants. To our knowledge, the proposed DRNG construction is the first to achieve all these properties.

Problem

• Designing post-quantum secure decentralized random number generation
• Achieving security without relying on the random oracle model
• Reducing communication rounds to two while tolerating t < n/2 dishonest participants

Innovation

• Post-quantum secure lattice-based PVSS DRNG
• Two-round communication for randomness generation
• Tolerates t < n/2 dishonest participants