Analysis of Quantum Key Distribution System Based on BB84 Protocol

The quantum cryptography has been concerned in worldwide after invention.Since it is the only way that can be proved to ensure the secure communication.The rapid development of quantum information technology makes quantum key distribution goes into the practical application from the theoretical research.For studying how the devices in practical quantum key distribution system based on the BB84 protocol effect the key distribution efficiency and improve the key distribution rate,a theoretic model relative to the system was represented,researched the parameter effects the key distribution efficiency.It was shown by the simulation that average photon number in the photon source and the length of optical fiber are the key parameters that affect the system rate.The work is useful for further improving the system efficiency.