Research On Semiquantum Secret Sharing

Quantum cryptography,as an important branch of quantum information,combines the laws of quantum mechanics and the characteristics of classical cryptography to accomplish the secret communication of information via the quantum channel.As one of the most important applications of quantum cryptography,quantum secret sharing(QSS),allows the secret key from the sender to be shared among different receivers in such a way that only all receivers cooperate together can they reveal it.In 2007,the ’semiquantumness’ concept was put forward for the first time,where a classical user is widely considered to be limited within the following operations:①transmitting particles via the quantum channel;②measuring particles in the z basis(i.e.,{|0>,|1>});③preparing the fresh particles in the z basis;and④reordering particles via different delay lines.Semiquantum secret sharing(SQSS)is the application of the concept of semiquantum to QSS,allowing only part of the participants to have complete quantum capabilities.Compared with the traditional QSS,it greatly reduces the burden of quantum resources and quantum operations.This paper mainly studies the design and analysis of SQSS protocols,and proposes three novel SQSS protocols.The main research results are as follows:(1)A SQSS protocol by using χ-type states is proposed.The protocol is designed by adopting χ-type states as the initial quantum resource,which can accomplish the goal that only when two classical communicants cooperate together can they extract the shared secret key of a quantum communicant.The protocol does not need share private keys among different participants beforehand,nor employ quantum entanglement swapping or unitary operations.And compared to the existing SQSS protocol also based on four-particle quantum entanglement states,it eases the burdens on the preparation of initial quantum resource and the usage of quantum entanglement swapping.(2)A multiparty semiquantum secret sharing(MSQSS)protocol based on d-dimensional single-particle states is put forward.This protocol uses d-dimensional single-particle states as the initial quantum resource.It transmits the single particles in a tree-type way and shares the secret information between N parties by modulo d summation.This protocol is suitable for the d-dimensional quantum system and has more advantages in the usage of unitary operations compared to the existing SQSS protocols based on d-dimensional quantum system.(3)A single-state MSQSS protocol with d-dimensional Bell states is constructed.This protocol is designed by only employing one kind of d-dimensional Bell states as initial quantum resource and exploiting the entanglement correlations between its different particles to accomplish the goal that only when all receivers work together can they restore the sender’s secret key.Compared to the existing SQSS protocols based on d-dimensional quantum system,this protocol has certain advantages in the number of initial quantum state and does not require quantum entanglement swapping or unitary operations,thus,more applicable.