Research On Measurement-device-independent Quantum Communication With Hyper-encoding

As the one of the most important branch of quantum information science,quantum communication uses quantum mechanical principles to manipulate quantum states to complete information interaction.Compared with classical communication,quantum communication is known for its unconditional security and efficiency.As a result of its huge application value and research value,in recent years,quantum communication technology based on quantum key distribution(QKD)and quantum secure direct communication(QSDC)has developed rapidly.Quantum key distribution protocol can realize unconditionally secure key transmission between sender Alice and receiver Bob.QSDC is completely different from QKD.It does not require key distribution,key storage and ciphertext transmission,and completely eliminates the encryption process.Therefore,it in principle avoids all security vulnerabilities related to keys and ciphertext in traditional secure communications.However,due to the defects of experimental equipment,the actual security of QKD and QSDC is challenged.At present,most of the attacks are mainly on the detector side,and the communication protocol of measurement device independent can just solve this problem,but its key generation rate and communication capacity have not been effectively improved.In order to improve the key generation rate and communication capacity,this paper proposes a measurement device independent communication protocol with hyper-encoding.The main work is divided into the following two points:1.We propose a measurement-device-independent quantum key distribution(MDI-QKD)protocol with hyper-encoding.We use single photons to encode in the spatial mode degrees of freedom and polarization degrees of freedom and retain the same coding information at any degree of freedom,which effectively improves the utilization of the security key.Secondly,through security analysis,it is shown that the key generation rate with hyper-encoding is higher than encoding of single degree of freedom,and the transmission distance is also extended.Finally,we improve the formula to improve the key generation rate.2.We propose a measurement-device-independent quantum security direct communication(MDI-QSDC)protocol with hyper-encoding.This scheme solves all attacks on the detector side and ensures the actual security of QSDC.In addition to the security advantages,the scheme isbased on linear optics to distinguish the hyper-entangled Bell states,which guarantees the unique discrimination of some hyper-entangled Bell states and effectively improves the communication capacity.