Quantum Secure Direct Communication by Using a GHZ State

Two schemes for quantum secure direct communication by using a Greenberger-Horne-Zeilinger (GHZ) state are proposed. The Bell-state measurement and the single-particle measurement are involved in our schemes. During the process of transmission of particles, the transmitted particles do not carry any secret messages and are transmitted only one time. We also show that the present schemes can efficiently resist intercept-and-resend attack, disturbance attack, and entangle-measure attack. KCI Citation Count: 20