The Design Of A New Quantum Multi-party Key Agreement Protocol

In order to achieve the purpose of secure transmission of secret information of multiple users on an open channel,in general,users participating in communication need to share a key in advance and use it for subsequent encryption and decryption of secret information.In the field of quantum cryptography,Quantum Key Agreement(QKA)is often used to complete key sharing.QKA is that all legal participants negotiate together,contribute equally,and finally share the key.No participant can determine the final key in advance.At present,there are still some loopholes in some Multiparty Quantum Key Agreement(MQKA)protocols.For example,participants independently determine the final key without being discovered,which makes the agreement unsatisfactory;Several dishonest legal participants conspired to forge the key without being discovered and determine the final shared key in advance,making the protocol unable to resist internal joint attacks.Therefore,satisfying fairness and successfully resisting joint attacks have become the focus and difficulty of multi-party quantum key agreement design.In view of the shortcomings of the existing MQKA protocol,this paper studies and designs two new multi-party quantum key agreement protocols that can meet fairness and successfully resist joint attacks.The specific work is as follows:(1)A multi-party quantum key agreement protocol based on quantum Fourier operation is proposed.Firstly,the protocol uses quantum Fourier operation and control U operation to add the key to the phase,and extracts the phase information by performing the inverse quantum Fourier operation to obtain the shared key.Secondly,by introducing tools such as random numbers,auxiliary particles,and hash functions with anti-collision,in the final stage of the protocol,it can effectively verify whether there are dishonest participants,so that the protocol can successfully resist internal joint attacks.At the same time,decoy states are used to ensure that the protocol can successfully resist external attacks.Finally,the correctness and safety of the article are analyzed and proved,and the efficiency analysis is also carried out.(2)A multi-party quantum key agreement protocol based on the Bell state entanglement is designed.Firstly,the protocol introduces a semi-honest server.The server prepares the Bell state,temporarily retains its first particles,and sends the second particles sequence to the participants.Participants use Pauli operations to encrypt their keys to the transmitted quantum state sequence.After the encryption process is over,the server sends the first particles to the corresponding participants.Participants use the entangled relationship of Bell state,and finally all participants can share the same key.Since they do not know the initial state,so protocol can successfully resist joint attacks.At the same time,using decoy states to make the protocol resistant to external attacks.Finally,analyze the correctness and security of the protocol.