Research On Privacy Protection In Quantum Communication Network

Privacy protection in communication network is the basic condition to ensure secure communication,and it is also an unavoidable difficult problem to promote social informatization.Traditional communication relies on the complexity of computation to avoid the eavesdropping of secret information,so a complete classical cryptographic system has been developed to encrypt and decrypt the transmitted privacy information to achieve the purpose of protecting privacy.However,with the emergence of quantum computers,classical cryptosystems will gradually be difficult to meet the next stage of privacy protection requirements.Since the first quantum communication protocol was published in 1998,researchers have gradually used quantum mechanics theory to design and study quantum communication protocols,in order to solve the unsolved security problems in classical communication and promote the development of communication technology.With the gradual development of quantum communication from theoretical stage to practical application,various fields of quantum communication begin to emerge,and a perfect research system has been formed.Quantum communication is mainly divided into: Quantum Key Distribution,Quantum Secret Sharing,Quantum Privacy Comparison and Quantum Secure Direct Communication,etc.This thesis takes semi-quantum secure direct communication and semi-quantum privacy comparison as the research object,and use quantum mechanics characteristics to realize the transmission of secret information and the comparison of privacy information in communication network,so as to ensure two directions of privacy protection in quantum communication network: one is user's personal privacy,such as identity security in the process of property comparison;the other is privacy protection in the process of communication.Information transmission security.Starting from two aspects,we can jointly maintain the privacy and security of quantum communication network.the design process of the two protocols is described in detail,and the corresponding security and efficiency analysis are given.Semi-quantum direct secure communication protocol solves the problem of how to ensure the secure transmission of privacy information in network communication.Privacy comparison protocol guarantees the user's privacy not to be disclosed but also to be able to detect and compare safely when the user's personal identity needs to be detected.In addition,the proposed two protocols include the participation of semi-quantum users.The participation of classical users reduces the cost of protocol implementation and expands the scope of application of quantum communication,and even promotes the development of quantum communication from theory to reality.The main contents of this thesis are as follows:(1)Semi-quantum secure direct communication protocol based on Bell state.In the protocol,quantum user Alice sends secret information directly to classical user Bob.Depending on the principle of quantum uncertainty and the entanglement of Bell states,the proposed protocol can detect eavesdropping and transfer secret information without additional decoy photon sequences to assist in eavesdropping detection.At the same time,the process of secret information transmission and eavesdropping detection is completely independent.Once the eavesdropper is found in the quantum channel,the communication is terminated immediately and the secret information is not disclosed by the previously sent ciphertext.In addition,the security analysis and efficiency comparison of the protocol are given.The analysis shows that the current protocol is not only more convenient in operation,but also more efficient than some of the current proposed protocols,which has a certain significance for the transmission of privacy information in quantum networks.(2)Semi-quantum privacy comparison protocol based on Bell state.Semi-quantum users Alice and Bob are able to compare their private information with the help of a semi-honest TP,without being intercepted by the other party and the eavesdropper.Compared to the previous QPC protocol,the protocol allows classic users to participate in quantum privacy comparisons,but limits their ability to measure,prepare,and reflect qubits on classical measurement basis.At the same time,the pre-shared key is used in the protocol process,which allows Alice and Bob to simultaneously select the same operation and thus resist participant attacks.