Efficient Three-Party Quantum Secure Direct Communication with EPR Pairs

In order to get rid of the drawback of information leakage which existed in Chong et al.’s protocol (Opt. Commun., 284, 2011, 515-518), an efficient three-party quantum secure direct communication (3P-QSDC) based on some ideas of quantum dense coding with EPR pairs is proposed, in which each entangled pair can be used to exchange a longer length of secret message between three legal users. By improving the classical channels and the qubit transmissions, our scheme can avoid this kind of drawback. Thus the secret messages are not leaked out to other people from the public information. Moreover, compared with Chong et al.’s protocol, our protocol can achieve higher efficiency.