Research On Blind Quantum Computation With Authentication Based On Sandglass-like Graph State

In Blind quantum computation（BQC）,the client with weak quantum computation capabilities is allowed to delegate its quantum computation tasks to a server with powerful quantum computation capabilities,and the inputs,algorithms and outputs of the quantum computation are confidential to the server.Verifiability is an ideal property of BQC protocol,which means that the client verifies whether the server has executed the protocol correctly with a certain probability.The verifiability of BQC includes the verifiability of only measured BQC and the verifiability of universal BQC.This thesis mainly concentrates on the verifiability of universal BQC,which is mainly realized by introducing trap qubits into the computation graph state and expanding it into a new graph state with verification function.On the premise of ensuring the original computation function,the detection of server deception is realized by trap qubits.In addition,in the actual computation process,there may be a outside malicious attacker to carry out impersonation attacks and man in the middle attacks on BQC.These attacks will also pose a great threat to BQC,so the identity authentication of participants in the BQC is also essential.Although the existing verifiable protocols based on universal BQC have achieved verifiability,the probability of receiving incorrect computation result by the clients of these protocols is still high;The existing blind quantum computation protocol with identity authentication need to introduce a trusted third party（TTP）with certain quantum capability,which improves the requirements for the overall quantum capability of BQC,and there is no BQC protocol that realizes both verifiability and identity authentication in the existing research.Therefore,focusing on verifiability and identity authentication,this thesis proposes two more secure and reliable BQC protocols.The specific research contents are as follows:1.A verifiable blind quantum computation protocol based on sandglass-like graph state is proposed.The protocol uses the sandglass-like graph state as the computation graph state.Firstly,a new coloring scheme is designed for the sandglass-like graph state,and then the positions of computation qubits,dummy qubits and trap qubits in the computation graph state are determined according to the coloring scheme.Finally,by verifying the measurement results of each trap qubit in the sandglass-like state by the server,the client can judge whether the server has correctly performed the computation and ensure the accuracy of the computation result.The protocol analysis shows that the protocol realizes the verification of the client to the computation result of the server without additional requirements for the quantum capability of the client,and reduces the probability of the client accepting the incorrect computation result from（7）0.8 66（8）^d*to（7）0.8 19（8）^d*,where d^*is the number of repeated execution of the protocol.2.A verifiable BQC protocol with authentication based on sandglass-like graph state is proposed.Based on the proposed“verifiable blind quantum computation protocol based on sandglass-like graph state”,the protocol integrates identity authentication into BQC.The protocol introduces a completely classical TTP.The client and server use the identity string applied by the TTP and the message sent in the process of communication to realize two-way identity authentication and ensure the integrity of the message.At the same time,it does not increase the requirements for the quantum capability of the client,nor does it increase the requirements for the overall quantum capability of BQC.The protocol analysis shows that the protocol not only has the same correctness,blindness and verifiability as the verifiable BQC protocol based on sandglass-like graph state,but also can resist impersonation attacks and man in the middle attacks.