Experimental transmission of quantum digital signatures over 90-km of installed optical fiber using a differential phase shift quantum key distribution system

摘要

Quantum digital signatures apply quantum mechanics to the problem ofguaranteeing message integrity and non-repudiation with information-theoreticalsecurity, which are complementary to the confidentiality realized by quantumkey distribution. Previous experimental demonstrations have been limited totransmission distances of less than 5-km of optical fiber in a laboratorysetting. Here we report the first demonstration of quantum digital signaturesover installed optical fiber as well as the longest transmission link reportedto date. This demonstration used a 90-km long differential phase shift quantumkey distribution system to achieve approximately one signed bit per second - anincrease in the signature generation rate of several orders of magnitude overprevious optical fiber demonstrations.