Quantum Key Agreement Protocols Based On Multi-Particle Entangled States

With the development of quantum technologies,quantum communication has become the focus of public attention.Compared to classical communication methods,quantum communication is theoretically absolutely secure because it is based on quantum physics principles.Quantum key agreement protocol is a quantum communication protocol,which refers to the protocol in which two or more participants jointly negotiate a shared key,and each participants’ contribution to the key is equal.In addition,multi-particle entangled state is an important physical resource in quantum information processing,and the more the number of particles,the more quantum advantages can be realized in quantum communication and quantum computing.In this paper,we propose three new quantum key agreement protocols to address the problems of low qubit efficiency,insecure authentication and limited quantum information capacity of the currently proposed quantum key agreement protocols.The contents are as follows.1.Considering the influence of collective noise on quantum key agreement protocol,a quantum key agreement protocol with collective noise resistance is proposed based on the measurement correlation of logical GHZ states.The qubit efficiency of the protocol is 28.57%,which is higher than other protocols under the influence of collective noise.2.A quantum key agreement protocol with identity authentication is proposed by using the six-particle entanglement states.This protocol requires neither a semi-trusted third party nor additional private key for identity authentication.The whole process of identity authentication and key agreement can be realized by using only 9)six particle entangled states(9)refers to the number of entangled states actually required).Therefore,it not only improves the security of the authentication process,but also saves communication costs.Security analysis shows that this scheme can also resist some important external attacks.3.A quantum key agreement protocol for three-dimensional systems is designed using three-dimensional GHZ states.Due to the increased dimensionality of the quantum system,the protocol has higher information capacity and better security.At the same time,the qubit efficiency of the proposed protocol is higher compared with similar quantum key agreement protocols.