Biometric authentication has become integral to digital identity systems, particularly in smart cities where it en-ables secure access to services across governance, trans-portation, and public infrastructure. Centralised archi-tectures, though widely used, pose privacy and scalabil-ity challenges due to the aggregation of sensitive biomet-ric data. Decentralised identity frameworks offer better data sovereignty and eliminate single points of failure but introduce new security concerns, particularly around mu-tual trust among distributed devices. In such environments, biometric sensors and verification agents must authenticate one another before sharing sensitive biometric data. Ex-isting authentication schemes rely on classical public key infrastructure, which is increasingly susceptible to quan-tum attacks. This work addresses this gap by propos-ing a quantum-secure communication protocol for decen-tralised biometric systems, built upon an enhanced Quan-tum Key Distribution (QKD) system. The protocol incorpo-rates quantum-resilient authentication at both the classical and quantum layers of QKD: post-quantum cryptography (PQC) is used to secure the classical channel, while authen-tication qubits verify the integrity of the quantum channel. Once trust is established, QKD generates symmetric keys for encrypting biometric data in transit. Qiskit-based sim-ulations show a key generation rate of 15 bits/sec and 89% efficiency. This layered, quantum-resilient approach offers scalable, robust authentication for next-generation smart city infrastructures.

翻译：生物特征认证已成为数字身份系统的关键组成部分，尤其在智慧城市中，它实现了对治理、交通和公共基础设施等服务的安全访问。集中式架构虽被广泛采用，但由于敏感生物特征数据的聚合，带来了隐私和可扩展性方面的挑战。去中心化身份框架提供了更好的数据主权并消除了单点故障，但也引入了新的安全问题，特别是分布式设备间的相互信任问题。在此类环境中，生物特征传感器与验证代理必须在共享敏感生物特征数据之前相互认证。现有的认证方案依赖于经典公钥基础设施，其日益容易受到量子攻击。本研究通过提出一种基于增强型量子密钥分发系统的去中心化生物特征系统量子安全通信协议，以解决这一不足。该协议在QKD的经典层和量子层均融入了量子弹性认证机制：后量子密码学用于保护经典信道，而认证量子比特则用于验证量子信道的完整性。一旦建立信任，QKD将生成对称密钥用于加密传输中的生物特征数据。基于Qiskit的模拟显示密钥生成速率为15比特/秒，效率达89%。这种分层、量子弹性的方法为下一代智慧城市基础设施提供了可扩展、鲁棒的认证方案。