Research On Participant Attacks In Quantum Cryptogrphic Protocols

Participant attack is an important research topic in cryptographic protocols,which is also the case for quantum cryptographic protocols.In contrast to external opponents,the participants know partial information legally and can escape detection owning to introducing no errors by lying in the eavesdropping check.Therefore,the study of participant attack in quantum cryptographic protocols is rather complicated,especially when multiple participants are involved.In this thesis,the participant attack problems in cryptographic protocols such as quantum digital signature,quantum secure multiparty sum,quantum secret sharing and quantum electronic contract signing are studied.The main achievements are as follow.Firstly,aiming at the multiparty quantum digital signature protocol given by Arrazola et al,we propose a new attack strategy,i.e.,a framing attack,whereby unreliable participants can make an honest participant be punished if they collude with each other.In order to resist this attack,we give the specific security requirements by studying the qualitative relations among signature key,verification key and different verification keys,and then present a feasible method to solve the security problem.Secondly,aiming at the quantum digital signature protocol for sensitive data access control given by Qiu et al,we propose a forgery attack and a repudiation attack.The first attack is based on known-message mode,in which the receiver can forge a signature for any message according to his own needs.The second attack is based on the way of intercept-resend,in which the signer can successfully deny her signature.Additionally,we propose a feasible way to solve these security problems by analyzing the specific reasons.Thirdly,aiming at the quantum secure multiparty summation protocol given by Sutradhar et al,we propose a deception attack and an intercept-replace attack.In the first attack,a dishonest participant can obtain the sum of all participants’ secret without being found while making other participants obtain a false sum.The second attack is based on the way of intercept-resend,in which a dishonest participant can not only obtain the sum of all participants’ secrets without being found but also other participants’ sub-secrets at the same time.Additionally,we propose a feasible way to solve the security problem by analyzing the specific reasons.Fourthly,aiming at the verifiable sequential threshold quantum secret sharing scheme given by Lu et al,we propose a measure-extract attack and a steal-deceive attack.In the first attack,the first participant can obtain the dealer’s secret with a certain probability without being found.In the second attack,the dishonest participants can obtain the dealer’s secret without being found while making other participants obtain a false one.Additionally,we propose a feasible way to solve the security problem by analyzing the specific reasons.Finally,we study the participant attack problems in quantum electronic contract signing,and then propose a practical scheme,which solves the difficult problem of long-time quantum storage.Furthermore,this protocol is based on single particles rather than entangled states,and therefore its physical implementation is more easy.In summary,we mainly study the participant attacks in quantum digital signature,quantum secure multiparty sum and quantum secret sharing.We give specific attack strategies and the corresponding solutions on some protocols respectively.On this basis,a new practical quantum electronic contract signing protocol is proposed,which can resist participant attacks effectively.