Economical quantum secure direct communication network with single photons

Abstract

A scheme for quantum secure direct communication (QSDC) network is proposed\nwith a sequence of polarized single photons. The single photons are prepared\noriginally in the same state |0> by the servers on the network, which will\nreduce the difficulty for the legitimate users to check eavesdropping largely.\nThe users code the information on the single photons with two unitary\noperations which do not change their measuring bases. Some decoy photons, which\nare produced by operating the sample photons with a Hadamard, are used for\npreventing a potentially dishonest server from eavesdropping the quantum lines\nfreely. This scheme is an economical one as it is the easiest way for QSDC\nnetwork communication securely.\n