Research On Two-way Quantum Secure Communication

Bidirectional quantum secure communication is one of the most important research topics in the field of quantum cryptography and plays a significant role in quantum communication.Bidirectional quantum secure communication is also known as quantum dialogue.Depending on whether there is a controller or not,it can be divided into two parts: controlled quantum dialogue and controllerindependent quantum dialogue.Both of these dialogue protocols have their advantages.In this paper,we make systematic study of these two quantum dialogue schemes.Firstly,we propose a controller-independent quantum dialogue protocol based on four-particle entanglement states.Meanwhile,the security of the proposed protocol is analyzed systematically.It can be seen from the security analysis that this protocol can successfully resist the severe information leakage problem.Moreover,the presented protocol can resist many existing attacks,including intercept-andresend attack,entangle-and-measure attack and fake entangled particles attack.Then,we propose a new controlled quantum dialogue protocol based on a kind of three-particle W-class states.Different from the above protocol,the third party controller who has a certain limit effect on communication process is introduced into the protocol.Security analysis shows that both the controller and the external eavesdropper cannot steal effective secret information.The communication users cannot realize quantum dialogue without the permission of the controller.Therefore,the requirement of controlled quantum dialogue is satisfied in our protocol.We hope that the two kinds of quantum communication protocols designed in this paper will be of positive significance to the research of bidirectional quantum secure communication.