摘要
In this paper we propose two quantum secure direct communication (QSDC) protocols with authentication.The authentication key expansion method is introduced to improve the life of the keys with security.In the first scheme,the third party, called Trent is introduced to authenticate the users that participate in the communication.He sends thepolarized photons in blocks to authenticate communication parties Alice and Bob using the authentication keys.In thecommunication process, polarized single photons are used to serve as the carriers, which transmit the secret messagesdirectly.The second QSDC process with authentication between two parties is also discussed.
基金
Supported by the National Fundamental Research Program under Grant No.2010CB923202
Specialized Research Fund for the Doctoral Program of Education Ministry of China under Grant No.20090005120008
the Fundamental Research Funds for the Central Universities under Grant No.BUPT2009RC0710
China National Natural Science Foundation under Grant Nos.60871082,60937003 and 10947151
