Tian Dongping，Shu Yuan，Zhong Bo
(School of Sciences,Xi'an Jiaotong University,Xi'an 710049,China)
Abstract：The quantum cryptography with focus on quantum key distribution (QKD) schemes is investigated. A new quantum cryptographic network is proposed, based on the point to point QKD scheme and the classical third party key distribution scheme. This quantum cryptographic network possesses many users and many centers, in which users store quantum states in quantum memories, and each transmission center is connected by quantum channels to all the users. The final key is dynamically generated during the processing. Each center only performs the correct projections on the Bell states and cannot get any information of the final key.
Keywords：quantum information;quantum cryptography;key distribution;quantum computer