QDBFT: A Dynamic Consensus Algorithm for Quantum-Secured Blockchain

2026-02-12

AI Summary

This work addresses the vulnerability of traditional blockchain systems to quantum attacks due to their reliance on classical cryptography and the high communication overhead and lack of quantum resistance in existing PBFT protocols during dynamic node changes. To overcome these limitations, the paper proposes QDBFT, a novel consensus protocol that integrates a consistent hashing ring for automatic leader rotation and efficient dynamic membership reconfiguration. Furthermore, QDBFT incorporates a quantum key distribution (QKD) network to ensure information-theoretic security for inter-node communication. By uniquely combining QKD with dynamic Byzantine fault-tolerant consensus, QDBFT achieves strong quantum attack resilience while maintaining performance comparable to PBFT, thereby offering an efficient and scalable consensus infrastructure for future quantum-safe consortium blockchains.

Technology Category

• Machine Learning: Quantum Machine Learning
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust
• Multiagent Systems: Mechanism Design

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Economics, Online Markets and Human Computation: Economic aspects of blockchain and cryptocurrencies
• Responsible Web: Consent frameworks and practices on the web

Abstract

The security foundation of blockchain system relies primarily on classical cryptographic methods and consensus algorithms. However, the advent of quantum computing poses a significant threat to conventional public-key cryptosystems based on computational hardness assumptions. In particular, Shor's algorithm can efficiently solve discrete logarithm and integer factorization problems in polynomial time, thereby undermining the immutability and security guarantees of existing systems. Moreover, current Practical Byzantine Fault Tolerance (PBFT) protocols, widely adopted in consortium blockchains, suffer from high communication overhead and limited efficiency when coping with dynamic node reconfigurations, while offering no intrinsic protection against quantum adversaries. To address these challenges, we propose QDBFT, a quantum-secured dynamic consensus algorithm, with two main contributions: first,we design a primary node automatic rotation mechanism based on a consistent hash ring to enable consensus under dynamic membership changes, ensuring equitable authority distribution; second, we integrate Quantum Key Distribution (QKD) networks to provide message authentication for inter-node communication, thereby achieving information-theoretic security in the consensus process. Experimental evaluations demonstrate that QDBFT achieves performance comparable to traditional PBFT while delivering strong resilience against quantum attacks, making it a promising solution for future quantum-secure decentralized infrastructures.

Problem

• quantum computing
• blockchain security
• Byzantine fault tolerance
• dynamic consensus
• post-quantum cryptography

Innovation

• Quantum Key Distribution
• Dynamic Consensus
• Byzantine Fault Tolerance
• Consistent Hashing
• Quantum-Secured Blockchain