| With rapid development of cryptanalysis technique and computational capabilities,classical cryptography faces the severe challenge.Nowadays most cryptography algorithms widely used in communication are based on the hard mathematic problems.It's security is lim-ited to the current computing capacity without complete demonstration.In addition,the research breakthrough of quantum search and factoring algorithm brings unprecedented se-curity threats to classical cryptography.Quantum cryptography,the combination of quantum mechanics principle and cryptogra-phy,provides researchers with a good solution.The security of quantum cryptosystem is guaranteed by the fundamental principles of quantum mechanics.Quantum cryptography has two basic characteristics what the classical cryptography without,i.e.unconditional se-curity and eavesdropping detecting.These advantages make quantum cryptography have good performance and broad application prospects,mainly including quantum key distribu-tion,quantum secret sharing,quantum secure direct communication,quantum dialogue and quantum authentication,etc.Focusing on the frontier research subjects of quantum cryptographic protocols,the main researchresults we obtained are as follows:(1)We propose a secure quantum dialogue protocol based on Bell states.The proposed protocol can realize the communication parties' secure exchange of their respective secret messages only through one transmission.In the protocol,a random bit string and detecting photons are used to guarantee the security.The protocol is secure against eavesdropper's commonly attacks,such as intercept/resend attack,Trojan horse attack and entanglement attack.Furthermore,our protocols can overcome the information leakage and its theoretical efficiency can reach 66.7%.At last,the scheme is generalized to the case with two-qutrit entangled states.(2)We propose a quantum dialogue protocol based on the two-qutrit entangled states.In the protocol,the security of communication is ensured by the secret transmitting order of the qutrits.Two legitimate users can directly transmit their secret messages by generalized Bell-basis measurement and announcements.The efficiency of this scheme is high,which can reach to 100%.Besides,the protocol is not only feasible in practice but also can discard the drawback "information leakage" or "classical correlation".(3)We propose a novel quantum dialogue protocol by using the generalized Bell states and entanglement swapping.In the protocol,a sequence of ordered two-qutrit entangled states acts as quantum information channel for exchanging secret messages directly and simul-taneously.Besides,a secret key string is shared between the communicants to overcome information leakage.Different from those previous information leakage resistant quantum dialogue protocols,the particles,composed of one of each pair of entangled states,are trans-mitted only one time in the proposed protocol.Security analysis shows that our protocol can overcome information leakage and resist several well-known attacks.Moreover,the effi-ciency of our scheme is acceptable.(4)We present a novel authenticated quantum dialogue protocol by using Bell states and entanglement swapping.Both sides of communication can implement mutual authentica-tion and carry out communication simultaneously.In this protocol,we adopt EPR pairs to detect eavesdropping and transmit secret messages.In addition,we employ polarized pho-tons to achieve authentication of users' identity information.Compared with other quantum dialogue schemes with authentication,our protocol has several advantages.The particles transferred carry none of the secret messages and are transmitted only one time.The pro-posed protocol is more secure because Alice randomly takes the unitary operations on all the checking groups before the particles are transmitted.Besides,it is more efficient be-cause each EPR pair can carry two bits secret messages.Furthermore,it can overcome the drawback of information leakage and resist against typical attacks. |
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