Quantum Secure Direct Communication Using W State

A theoretical scheme of quantum secure direct communication usingteleportation is proposed. In the scheme, the sender needs to prepare aclass of three-particle W states to use as quantum channel. The twocommunicators may communicate after they test the security of thequantum channel. The security of the protocol is ensured by quantumentanglement and quantum no-cloning theorem. The receiver can obtain thesecret message determinately if the quantum channel is secure.