Bidirectional Quantum Secure Direct Communication Based on Entanglement

Based on entanglement,a bidirectional quantum secure direct communication scheme is proposed to exchange directly the communicators' secret messages. In this scheme the messages are encoded in the entanglement state. our scheme has great capacity to distribute the secret messages since these messages have been imposed on high-dimensional Bell states via the local unitary operations with superdense coding. Security analysis indicates that this scheme is secure against the present Trojan horse attack and the current attack strategyand it can also ensure the security of the messages in a low noisy channel.