Study On The Security Of Quantum Channel And Two-way Teleportation With Several Controllers

Information security plays an increasingly important role in human social life.With the round development of the current information age,the classic secret communication based on the calculation complexity is facing enormous challenges.Thus there rises a new communication technology-quantum communication.As an important research direction of communication,quantum communication which consists of information theory and quantum theory developes rapidly.In the process of information transmission,it uses the characteristics of quantum mechanics.From the perspective of information science,quantum communication uses quantum no-cloning,quantum teleportation and other quantum properties to achieve information transmission by quantum measurement between two different places.In the view of physics,quantum communication is the high-performance communication using quantum effects at the physical limits,to ensure the absolute safety of communication on physical principles.Compared with the traditional communication technology,quantum communication has a great advantage in addressing security issues for which uses the properties of microscopic particles.It is expected to become one of the communication mode of higher security.In this paper,we consider the security of quantum communication from two aspects.On the one hand,we study the security capacity of the channel from the perspective of the physical layer security on the basis of the quantum information theory.As we all known,they can achieve absolute security of information transmission when the information transmission rate is less than the channel capacity of security.On the other hand,we analyse the appropriate quantum teleportation ways to improve the security of communication to some extent.The main contents are as follows:On the basis of Wyner eavesdropping channel security capacity,combined with quantum theory and information theory,we study the security capacity of classic-quantum composite eavesdropping channel in which the legitimate transmission channel sets is classical channels and the eavesdropping channel sets is quantum channels in the process of communication.When the sender knows the channel state information,we deduce security capacity of the channel.At the same time,we come to the lower bound of security capacity of the channel at the sender does not know the channel state information.On communication,combined with the security and teleportation actual ease of quantum communication,a new two-way quantum teleportation scheme with several controllers is proposed.In the theoretical scenario,there are three controllers to assist the communication and the entangled resources are the maximum seven-particle entangled states.Before communication,Alice,Bob and three controllers secretly share the maximum seven particle entangled state to construct quantum channel.In a certain extent,three controllers' involvement improve the security of the communication and avoid the measurement complexity of a joint three-particle implementation.