Design And Analysis Of Quantum Key Distribution Protocols Based On Hybrid Entanglement And High-dimensional Quantum States

Constantly exploring the optimization methods of quantum key distribution scheme,designing efficient quantum key distribution protocols and fully proving the security of protocols theoretically are particularly important for establishing a complete theoretical system of quantum secret communication and promoting the practical development of quantum cryptography in the future.Aiming at the defects of low quantum entanglement resource utilization and limited key distribution rate in the existing schemes,two quantum key distribution schemes are designed respectively based on the random hybrid quantum channel and the high-dimensional quantum Hilbert space.The main research works of this dissertation are as follows:To improve the utilization of entanglement resources in traditional quantum key distribution systems,a theoretical quantum key distribution scheme based on random hybrid quantum channel with EPR pairs and GHZ states is devised.In this scheme,EPR pairs and tripartite GHZ states are integrated into a new coding framework to realize the key distribution task using quantum dense coding.The established hybrid quantum entanglement channel has flexibility,economy and confidentiality,where only one photon in each entangled state needs to run forth and back.Moreover,the security of the proposed quantum key distribution scheme is guaranteed by more than one round of eavesdropping check procedures and the decoy state method.In the ideal noise-free channel,the proposed scheme can resist intercept-measure-resend attack and the entanglement particle attack.In the actual noisy channel,the security of the proposed scheme should be guaranteed with the entanglement purification and the quantum privacy amplification.To break the information efficiency limit of traditional quantum key distribution schemes,an efficient high-dimensional quantum key distribution protocol based on the quantum Fourier transform is designed to further enhance the secret key rate and increase the channel transmission capacity.In the proposal,the inherent encoding framework provides a secure solution for key distribution,where the secret information can be encoded into the relative phases of the generated high-dimensional entangled state by performing the quantum Fourier transform and the quantum controlled-NOT gate.After reverse operations are carried out,the key information can be decoded with the single-particle measurement.The secret information in the form of high-dimensional quantum state throughout the proposed scheme leads to more secret key bits per round.Furthermore,the security of the particle transmission is guaranteed by the decoy state method,the secret key rate of the protocol and the security of the protocol under special attack strategies are analyzed,including the intercept-measure-resend attack,the entanglement particle attack,the photon number splitting attack and the side-channel attack.