Abstract: This paper proposes a new three-party quantum secure direct communication protocol with authentication. The scheme uses three-particle partially entangled states and CNOT gate to encode and decode. Two users can simultaneously transmit secret message to the third party, and partially entangled states shared can be used repeatedly. In ideal channel, the protocol is secure against incoherent attack. The advantage of the scheme is that through authentication, one can confirm the client’s legitimate identity, partially entangled states are easy to prepare and store in practice, and two users can simultaneously communicate with the third party.
quantum secure direct communication,
partially entangler state