Quantum Secure Direct Communication Using W State

A theoretical scheme of quantum secure direct communication using teleportation is proposed. In the scheme, the sender needs to prepare a class of three-particle W states to use as quantum channel. The two communicators may communicate after they test the security of the quantum channel. The security of the protocol is ensured by quantum entanglement and quantum no-cloning theorem. The receiver can obtain the secret message determinately if the quantum channel is secure.