Using Symmetry Dicke State as Security Detection Particle in Quantum "Ping-Pong" Protocol

Quantum Mechanics is one of the basic theories in modern physics, which has been widely used in many modern applications. In order to transmit a secure message, the deterministic secure quantum direct communication protocol was proposed. It has attracted great interest of researchers afterwards. But the protocol was proved to have many vulnerabilities, and can be attacked by eavesdropper. Many researchers have tried to improve it, with the concentration on the security detection strategy. In this paper, the symmetry Dicke state is used to detect eavesdropper. The quantum direct communication protocol that uses symmetry Dicke state as security detection particle and the method of entropy theory are introduced, and three detection strategies are compared. During the security analysis, we found that the efficiency of the proposed mothed is higher than the original "Ping-Pong" Protocol and the mothed that use two particles of EPR pair.