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.

翻译：区块链系统的安全基础主要依赖于经典密码学方法和共识算法。然而，量子计算的出现对基于计算复杂性假设的传统公钥密码体系构成了重大威胁。特别是，Shor算法能够在多项式时间内高效解决离散对数和整数分解问题，从而破坏现有系统的不可篡改性与安全保障。此外，当前在联盟链中广泛采用的实用拜占庭容错（PBFT）协议存在通信开销高、应对动态节点重配置时效率有限的问题，且不具备抵御量子攻击的内在防护能力。为应对这些挑战，我们提出了QDBFT——一种量子安全的动态共识算法，其主要贡献包括：首先，我们设计了一种基于一致性哈希环的主节点自动轮换机制，以支持动态成员变更下的共识达成，确保权威的公平分配；其次，我们集成量子密钥分发（QKD）网络为节点间通信提供消息认证，从而在共识过程中实现信息论安全。实验评估表明，QDBFT在保持与传统PBFT相当性能的同时，具备强大的抗量子攻击能力，使其成为未来量子安全去中心化基础设施的有前景的解决方案。