Three-party quantum dialogue based on Grover’s algorithm with identity dual authentication

Based on the study of quantum dialogue and quantum identity authentication, this paper proposes an improved three-party quantum dialogue (3P-QD) with dual authentication of identity protocol based on quantum search algorithm (QSA) and bidirectional verification of user identity. The protocol utilizes two-particle states as quantum resources to achieve bidirectional transmission of information in the channel and uses the non-cloning theorem of quantum mechanics, which ensures that sequences of quantum bits can be reliably and securely guaranteed during transmission. The characteristics of the QSA in the two-qubit are applied to the target state search process of this 3P-QD protocol, which can accomplish the task of safely transferring two bits of information between the two communicating parties. In addition, in the communication, one of the fixed third party is not only a communicating party, but also acts as a controller for the other two parties. Meanwhile, in order to ensure the security and integrity of the communication, a bidirectional authentication step is added to the communication process, which well solves the problem of eavesdropping. Based on the above features, compared with the existing protocols, this protocol has better advantages.