Experimental quantum Byzantine agreement on a three-user quantum network with integrated photonics

• DOI: 10.1126/sciadv.adp2877
• Publication Date: 2024-08-23T17:58:55Z
• Authors: Xu Jing; Cheng Qian; Chen-Xun Weng; Bing-Hong Li; Zhe Chen; Chen-Quan Wang; Jie Tang; Xiao-Wen Gu; Yue-Chan Kong; Tang-Sheng Chen; Hua-Lei Yin; Dong Jiang; Bin Niu; Liang-Liang Lu
• Keywords: Quantum key distribution; Quantum superposition

Quantum communication networks are crucial for both secure and cryptographic networked tasks. Building quantum in a scalable cost-effective way is essential their widespread adoption. Here, we establish complete polarization entanglement–based fully connected network, which features an ultrabright integrated Bragg reflection waveguide source, managed by untrusted service provider, streamlined analysis module, requires only one single-photon detector each user. We perform continuously working entanglement distribution create correlated bit strings between users. Within the framework of one-time universal hashing, provide experimental implementation source-independent digital signatures using imperfect keys circumventing necessity private amplification. further beat 1/3 fault tolerance bound Byzantine agreement, achieving unconditional security without relying on sophisticated techniques. Our results offer affordable practical route addressing consensus challenges within emerging network landscape.