Research On Two Types Of Quantum Key Distribution Protocols

Quantum cryptography is an interdisciplinary discipline that combines the basic principles of quantum mechanics with classical cryptography.Different from classical cryptography,its security does not depend on unverified computational complexity assumptions.Instead,it relies on the physics of quantum no-cloning theorem and Heisenberg uncertainty principle to ensure the theoretical unconditional security of secret information exchange.The semiquantum key distribution protocol means that the classical party can generate a secure key with the quantum side,while the classical party is limited to perform the following quantum operations:(1)access quantum channels,(2)measure qubits in the classical {0,1} basis,(3)prepare qubits in the classical {0,1} basis and(4)reorder qubits.The class of device-independent quantum key distribution protocol can guarantee the unconditional security of the key distribution but does not need to know the specific information of the quantum key distribution device,so it can remove the side channel attacks caused by the imperfection of the device.The main research content of this thesis involves the study of semiquantum key distribution protocols and device-independent quantum key distribution protocols.The main work is as follows:1.Propose a measurement-device-independent semiquantum key distribution(MDI-SQKD)protocolBased on the typical semiquantum key distribution protocol and the technology of measurement-device-independent,a measurement-device-independent semiquantum key distribution protocol is proposed and its security is analyzed.This protocol does not require both participants of the communication to measure the quantum state.Instead,it performs Bell state measurements with the help of an untrustworthy third party.At the same time,the legitimate communication parties analyze the security of the protocol based on the results published by the third party and the characteristics of quantum entanglement.This protocol not only removes the side channel attacks due to its limperfect devices,but also allows ordinary users with limited quantum resources to cooperate with the quantum party to obtain a secure key.2.Propose a one-side measurement-device-independent semiquantum key distribution(1SMDI-SQKD)protocolA 1SMDI-SQKD protocol is proposed based on the protocol of MDI-SQKD.The encoding system of quantum side in this protocol is uncharacterized,as long as its quantum state is prepared in a two-dimensional Hilbert space,this reduces the quantum side's security assumptions,and it combines the idea of decoy state to remove the photon number separation attack caused by multi-photon pulses and solve the problem that the ideal single photon source is difficult to prepare.