A quantum broadcast communication and authentication protocol with a quantum one-time pad based on the Greenberger–Horne–Zeilinger state is proposed. A binary string is used to express the identity of the receiver, which is encoded as a single sequence of photons. The encoded photon sequence acts as a detection sequence and implements authentication. An XOR operation serves as a one-time pad and is used to ensure the security of the protocol. The binary string is reused even in a noisy channel and proves to be unconditionally secure. In contrast with the protocols proposed by Wang et al. [Chin. Phys. 16 1868(2007)] and Yang et al. [Chin. Phys. B 19 070304(2010)], the protocol in this study implements the identity authentication with a reusable binary string; no hash function or local unitary operation is used. The protocol in this study is also easier to implement and highly efficient without losing security.
A quantum secure direct communication and authentication protocol is proposed by using single photons.An information transmission is completed by sending photons once in quantum channel,which improves the efficiency without losing the security.The protocol encodes identity-string of the receiver as single photons sequence,which acts as detection sequence and implements authentication.Before secret message is encoded as single photons sequence,it is encrypted with identity-string of the sender by using XOR operation,which defends quantum teleportation attack efficiently.The base identity-strings of the sender and the receiver are reused unconditionally secure even in noisy channel.Compared with the protocol proposed by Wang et al.(Phys Lett A,2006,358:256–258),the protocol in this study sends photons once in one transmission and defends most attacks including‘man-in-the-middle’attack and quantum teleportation attack efficiently.