Experimental demonstration of complete quantum e-commerce based on an efficient quantum digital payment

With the rapid spread of Internet technology, e-commerce is gradually becoming an integral part of the modern business models. The e-commerce transactions should obey integrity, authentication, nonrepudiation, traceability, and impartiality. Here, we propose and demonstrate a complete continuous-variable quantum e-commerce scheme, which involves subscription, payment, transport, and reception protocols among five parties. To this end, a simple, efficient quantum digital payment scheme is proposed. Furthermore, we streamline the entire e-commerce process by eliminating the private amplification step in the pre-distribution of keys. We achieve a contract signing rate of 1.51 x 103 times per second for a 33 kilobits contract, and a payment rate of 2.70 x 103 times per second over 80 km of single-mode fiber. Our results can support 411 times complete transactions per second, including three contract signings and two separate monetary payments. The proposed scheme takes into account the compatibility with existing e-commerce platforms to ensure a smooth transition and provides a practical solution for quantum e-commerce at metropolitan distances. (c) 2025 Chinese Laser Press