Research On Semiquantum Private Comparison

Quantum cryptography relies on the relevant principles of quantum mechanics to ensure the security of communication.As a branch of quantum cryptography,semiquantum cryptography does not require all participants to have complete quantum capabilities,so it can not only ensure the communication security of cryptographic protocols,but also effectively save quantum resources,thus improving the feasibility.Semiquantum private comparison is a research direction of semiquantum cryptography,which aims to compare the equality or size relationship of secret inputs without disclosing the content of the inputs.In this paper,we have carried out some new exploration and research on semiquantum private comparison,and designed three protocols,including two semiquantum private comparison protocols based on Bell states to achieve equality comparison and one semiquantum private comparison protocol based on d-level single-particle states to achieve size relationship comparison.The details are as follows:(1)A semiquantum private comparison protocol based on single kind of Bell states is proposed,which uses the entanglement correlation of Bell states to skillfully compare the equality of two classical users’ secret inputs.The protocol only needs to prepare single kind of Bell states as initial quantum resource,and it does not need quantum entanglement swapping or the reordering operations,so it reduces the initial quantum resource and quantum operation of semiquantum private comparison protocol.(2)A novel semiquantum private comparison protocol based on Bell states is proposed.Its purpose is to correctly and safely compare the secret input of one quantum user and one classical user.The protocol only asks TP to perform Bell basis measurements but doesn’t need quantum entanglement swapping;and it releases the classical user from conducting quantum measurements and having a quantum memory.Moreover,the proposed protocol can be generalized into its counterpart of the collective-dephasing noise quantum channel.(3)A semiquantum private comparison protocol of size relationship based on d-level single-particle states is proposed.The designed protocol can compare the size relationship of different privacy messages from two classical users with the help of a semi-honest third party.Moreover,this protocol only adopts d-level single-particle states as initial quantum resource,only requires TP to perform d-level single-particle measurements and makes TP have no access to the accurate comparison results.