Quantum Secure Direct Communication Using Six-Particle Maximally Entangled States and Teleportation

The sender shares six-particle maximally entangled states as quantumchannel with the receiver. If the quantum channel is secure, the sender performs projective measurements and tells the measurement outcome to the receiver. The receiver performs the unitary transformations and makes projective measurements on his particles to obtain the secret information. Using teleportation, the transmission of three-qubit secret information can be completed in each quantum channel.