By analyzing the basic properties of unitary transformations used in a quantum secure direct communication (QSDC) protocol, we show the main idea why a covert channel can be established within any QSDC channel which e...By analyzing the basic properties of unitary transformations used in a quantum secure direct communication (QSDC) protocol, we show the main idea why a covert channel can be established within any QSDC channel which employs unitary transformations to encode information. On the basis of the fact that the unitary transformations used in a QSDC protocol are secret and independent, a novel quantum covert channel protocol is proposed to transfer secret messages with unconditional security. The performance, including the imperceptibility, capacity and security of the proposed protocol are analyzed in detail.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.61170272, 61272514, 61003287, and 61070163Asia Foresight Program under National Natural Science Foundation of China under Grant No.61161140320+4 种基金the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20100005120002the Fok Ying Tong Education Foundation under Grant No.131067the Shandong Provincial Natural Science Foundation, China under Grant No.ZR2011FM023the Shandong Province Outstanding Research Award Fund for Young Scientists of China under Grant No.BS2011DX034the Fundamental Research Funds for the Central Universities under Grant No.BUPT2012RC0221
文摘By analyzing the basic properties of unitary transformations used in a quantum secure direct communication (QSDC) protocol, we show the main idea why a covert channel can be established within any QSDC channel which employs unitary transformations to encode information. On the basis of the fact that the unitary transformations used in a QSDC protocol are secret and independent, a novel quantum covert channel protocol is proposed to transfer secret messages with unconditional security. The performance, including the imperceptibility, capacity and security of the proposed protocol are analyzed in detail.
