Deterministic Secure Direct Communication by Using Swapping Quantum Entanglement and Local Unitary Operations

A deterministic direct quantum communication protocol is proposed by using swapping quantum entanglement and local unitary operations. The present protocol is secure for the proof of the security of the present scheme, the same as that in the two-step protocol Phys. Rev. A 68(2003)042317. Additionally, the advantages and disadvantages of the present protocol is also discussed.