Steganalysis and improvement of a quantum steganography protocol via a GHZ_4 state  

作　　者：徐淑奖 陈秀波 钮心忻 杨义先 

机构地区：[1]Information Security Center,State Key Laboratory of Networking and Switching Technology,Beijing University of Posts and Telecommunications [2]Shandong Provincial Key Laboratory of Computer Network,Shandong Computer Science Center [3]State Key Laboratory of Information Security,(Institute of Information Engineering,Chinese Academy of Sciences)

出　　处：《Chinese Physics B》2013年第6期199-202,共4页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 61170272,61272514,61003287,and 61070163);the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100005120002);the Fok Ying Tong Education Foundation (Grant No. 131067);the Natural Science Foundation of Shandong Province,China (Grant No. ZR2011FM023);the Outstanding Research Award Fund for Young Scientists of Shandong Province,China (Grant No. BS2011DX034);the Fundamental Research Funds for Central Universities of China (Grant No. BUPT2012RC0221)

摘　　要：Quantum steganography that utilizes the quantum mechanical effect to achieve the purpose of information hiding is a popular topic of quantum information. Recently, E1 Allati et al. proposed a new quantum steganography using the GHZ4 state. Since all of the 8 groups of unitary transformations used in the secret message encoding rule change the GHZ4 state into 6 instead of 8 different quantum states when the global phase is not considered, we point out that a 2-bit instead of a 3-bit secret message can be encoded by one group of the given unitary transformations. To encode a 3-bit secret message by performing a group of unitary transformations on the GHZ4 state, we give another 8 groups of unitary transformations that can change the GHZ4 state into 8 different quantum states. Due to the symmetry of the GHZ4 state, all the possible 16 groups of unitary transformations change the GHZ4 state into 8 different quantum states, so the improved protocol achieves a high efficiency.Quantum steganography that utilizes the quantum mechanical effect to achieve the purpose of information hiding is a popular topic of quantum information. Recently, E1 Allati et al. proposed a new quantum steganography using the GHZ4 state. Since all of the 8 groups of unitary transformations used in the secret message encoding rule change the GHZ4 state into 6 instead of 8 different quantum states when the global phase is not considered, we point out that a 2-bit instead of a 3-bit secret message can be encoded by one group of the given unitary transformations. To encode a 3-bit secret message by performing a group of unitary transformations on the GHZ4 state, we give another 8 groups of unitary transformations that can change the GHZ4 state into 8 different quantum states. Due to the symmetry of the GHZ4 state, all the possible 16 groups of unitary transformations change the GHZ4 state into 8 different quantum states, so the improved protocol achieves a high efficiency.

关 键 词：quantum steganography GHZ4 entangled state quantum cryptography quantum communication 

分 类 号：O413.1[理学—理论物理] TN918[理学—物理]