Research Of Multi-Access Quantum Communication Protocol

With the development of science and technology, quantum informatics has been a field that modern physics and computer science concerns. It is based on the basis of quantum mechanics theory. It is also a new developing and applied direction in quantum m-echanics. Quantum informatics includes two parts: quantum computing and quantum c-ommunication. And quantum communication includes quantum dense coding, quantumkey distribution, quantum teleportation, quantum security direct passing communication. Quantum key distribution and quantum teleportation are two important parts in quantum informatics. Using nocloning of quantum state and quantum teleportation instantaneity, high efficiency and safety in classic communication can be improved to a new level, and upgrade to quantum communication. In order to improve the quantum communication efficiency, the quantum secret sharing of multiparticle is studied, and on the basis of secret sharing, multi-access quantum network communication protocol is realized to reduce the transmission delay and repeated transmission in communication process. Commu-nication efficiency is improved and the burden of classic channel is reduced.This paper introduces the basic concept and theory of quantum communication, emphatically introduces quantum teleportation technology, quantum cloning technology and quantum network communication protocols, the research contents are presented asfollows:First: With GHZ state as a quantum channel, quantum bit secret sharing can berealized after transmitting the classical information by a classical channel. Based onthe above thoughts, making full use of the correlation of a six-particle entanglement G HZ state, via a Bell measurement, four single-particle measurements and the corresponding unitary transformation, a four-qubit secret sharing scheme can be achieved.Second: A multi-access quantum network communication protocol is proposed. That means quantum swapping technology, quantum cloning technology and leased network technology in classic communication are combined together to achieve an upgrade from classic multi-access network communication protocol to quantal one, and show the transmission of single particle and entangled particles. In the protocol, the sender judgesthe quantum frames which need to resend according to the received confirm frames in setting time. Quantum cloning technology is utilized and only the quantum frames among several users which are lost or error needs to resend, so it reduces the transmission delay and repeated transmission. Communication efficiency is improved and the burden ofclassic channel is reduced. Finally, the security of the protocol is briefly analyzed.