Quantum secure direct communication is the direct communication of secret messages without need for establishing a shared secret key first.In the existing schemes,quantum secure direct communication is possible only w...Quantum secure direct communication is the direct communication of secret messages without need for establishing a shared secret key first.In the existing schemes,quantum secure direct communication is possible only when both parties are quantum.In this paper,we construct a three-step semiquantum secure direct communication(SQSDC)protocol based on single photon sources in which the sender Alice is classical.In a semiquantum protocol,a person is termed classical if he(she)can measure,prepare and send quantum states only with the fixed orthogonal quantum basis{|0,|1}.The security of the proposed SQSDC protocol is guaranteed by the complete robustness of semiquantum key distribution protocols and the unconditional security of classical one-time pad encryption.Therefore,the proposed SQSDC protocol is also completely robust.Complete robustness indicates that nonzero information acquired by an eavesdropper Eve on the secret message implies the nonzero probability that the legitimate participants can find errors on the bits tested by this protocol.In the proposed protocol,we suggest a method to check Eves disturbing in the doves returning phase such that Alice does not need to announce publicly any position or their coded bits value after the photons transmission is completed.Moreover,the proposed SQSDC protocol can be implemented with the existing techniques.Compared with many quantum secure direct communication protocols,the proposed SQSDC protocol has two merits:firstly the sender only needs classical capabilities;secondly to check Eves disturbing after the transmission of quantum states,no additional classical information is needed.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.61272058 and 61073054)the Natural Science Foundation of Guangdong Province of China(Grant Nos.10251027501000004 and S2012040007324)+1 种基金the Specialized Research Fund for the Doctoral Programof Higher Education of China(Grant No.20100171110042)the Science and Technology Project of Jiangmen City of China(Grant No.[2011]131)
文摘Quantum secure direct communication is the direct communication of secret messages without need for establishing a shared secret key first.In the existing schemes,quantum secure direct communication is possible only when both parties are quantum.In this paper,we construct a three-step semiquantum secure direct communication(SQSDC)protocol based on single photon sources in which the sender Alice is classical.In a semiquantum protocol,a person is termed classical if he(she)can measure,prepare and send quantum states only with the fixed orthogonal quantum basis{|0,|1}.The security of the proposed SQSDC protocol is guaranteed by the complete robustness of semiquantum key distribution protocols and the unconditional security of classical one-time pad encryption.Therefore,the proposed SQSDC protocol is also completely robust.Complete robustness indicates that nonzero information acquired by an eavesdropper Eve on the secret message implies the nonzero probability that the legitimate participants can find errors on the bits tested by this protocol.In the proposed protocol,we suggest a method to check Eves disturbing in the doves returning phase such that Alice does not need to announce publicly any position or their coded bits value after the photons transmission is completed.Moreover,the proposed SQSDC protocol can be implemented with the existing techniques.Compared with many quantum secure direct communication protocols,the proposed SQSDC protocol has two merits:firstly the sender only needs classical capabilities;secondly to check Eves disturbing after the transmission of quantum states,no additional classical information is needed.
