| Abstract: | A quantum steganography protocol with a large payload is proposed based on the dense coding and the entanglement swapping of the Greenberger-Horne-Zeilinger (GHZ) states. Its super quantum channel is formed by building up a hidden channel within the original quantum secure direct communication (QSDC) scheme. Based on the original QSDC, secret messages are transmitted by integrating the dense coding and the entanglement swapping of the GHZ states. The capacity of the super quantum channel achieves six bits per round covert communication, much higher than the previous quantum steganography protocols. Its imperceptibility is good, since the information and the secret messages can be regarded to be random or pseudo-random. Moreover, its security is proved to be reliable. |
