Quantum computing provides the feasible multi-layered security challenges to classical blockchain systems. Quantum blockchains that relies on quantum key distribution (QKD) to establish secure channels can address this feasible threat. Whereas, there are still architecture limitations to practical security resulted in the measurement devices while implementing the QKD-based blockchains in physical layer. This paper presents a distributed architecture in quantum blockchain to address the connectivity and distance limitations of the QKD-secured networks. A decoupled architecture is designed felicitously so that it pairs a linearly scalable measurement-device-independent (MDI) physical layer with a decentralized consensus.It can optimize the complexity of infrastructure from quadratic to linear scaling, ascribed to leveraging the twin-field (TF) QKD protocol with the MDI-structurized star topology. Additionally, the dual-key stratification strategy transforms symmetric information-theoretic security into publicly auditable forward-secret blockchain evidence. This architecture can integrate information-theoretic security with distributed consensus mechanisms, allowing the scalable system to overcome the potential rate-loss limits inherent in traditional security-weakened blockchains.

翻译：量子计算对经典区块链系统构成了多层次的安全挑战。依赖量子密钥分发（QKD）建立安全通道的量子区块链可以应对这一潜在威胁。然而，在物理层实现基于QKD的区块链时，测量设备仍会导致实际安全性的架构限制。本文提出了一种量子区块链中的分布式架构，以解决QKD安全网络的连接性和距离限制。该架构通过巧妙设计解耦结构，将线性可扩展的测量设备无关（MDI）物理层与去中心化共识算法配对。得益于采用MDI结构化星型拓扑的双场（TF）QKD协议，基础设施的复杂度从二次方优化为线性增长。此外，双密钥分层策略将信息论安全性转化为可公开审计的前向安全区块链证据。该架构能够将信息论安全性与分布式共识机制相结合，使可扩展系统克服传统安全性弱化区块链固有的潜在速率-损耗限制。