Communications in Theoretical Physics
Improvement on Quantum Secure Direct Communication with W State in Noisy Channel
Li Dong, Xiu Xiao-Ming, Gao Ya-Jun, Chi Feng
Abstract
An improvement (Y-protocol) [Commun. Theor. Phys. 49 (2008) 103] on the quantum secure direct communication with W state (C-protocol) [Chin. Phys. Lett. 23 (2006) 290] is proposed by Yuan et al. The quantum bit error rate induced by eavesdropper is 4.17% in C-protocol and 6.25% in Y-protocol. In this paper, another improvement on C-protocol is given. The quantum bit error rate of the eavesdropping will increase to 8.75%, which is 1.1 times larger than that in C-protocol and 0.4 times larger than that in Y-protocol.