Reply to the Comment on “Improvement of Controlled Bidirectional Quantum Direct Communication Using a GHZ State" [Chin. Phys. Lett. 30 (2013) 040305]

Abstract

Most recently, Liu and Chen [Chin. Phys. Lett. 30 (2013) 079901] used the tool of information theory to analyze the security of our two improved versions of the MX protocol [Chin. Phys. Lett. 30 (2013) 040305], and they found out that our two improved versions still have the information leakage problem. After revisiting them with the tool of information theory again, with respect to the security, we draw the same conclusion as Liu and Chen. In addition, we point out that how to use a single quantum state as the sole quantum resource to design a bidirectional quantum secure direct communication protocol without information leakage is still a big challenge that needs to be solved.

A Kind of Quantum Dialogue Protocols Without Information Leakage Assisted by Auxiliary Quantum Operation

“…Also, the effectiveness of this method towards Eve's above active attacks has been fully analyzed in Refs. [10,13].…”

“…Suppose that Alice and Bob expect to transmit bits 10 and 01 to each other, respectively. After receiving particles a and b, Bob imposes U EX on particles a and b. Consequently, the |W abc evolves in a manner shown as (13). Then Bob performs Z-basis measurement on particle a to know its state.…”

“…Since it was independently suggested by Zhang et al [1,2] and Nguyen [3] in 2004, a lot QD protocols [4][5][6][7][8][9][10][11][12][13] had been proposed by many scholars. However, Tan and Cai [14] found out in 2008 that there may exist "classical correlation" in QD.…”

Multi-user quantum key distribution with collective eavesdropping detection over collective-noise channels

“…Since the pioneering work of Bennett and Brassard in 1984 [1], quantum cryptography has attracted a great deal of attention and has become one of the most promising applications of quantum information processing. There are several remarkable branches of quantum cryptography, including quantum key distribution (QKD) [1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11], [12], [13], [14], quantum secure direct communication (QSDC) [15], [16], [17], [18], [19], [20], [21], quantum secret sharing (QSS) [22], [23], [24], [25], [26], [27], and secure multi-party computation (SMC) [28], [29], [30], [31], [32]. As one of the most important parts of quantum cryptographic protocols, the multi-party quantum cryptographic protocol (MQCP) which involves at least three participants, such as quantum private comparison (QPC) protocols and QSS protocols, are more complicated than the two-party ones.…”

Large Payload Bidirectional Quantum Secure Direct Communication Without Information Leakage

“…21 However, as pointed out in Refs. 36 and 37, Ye's two improved protocols 35 still have the information leakage problem. Actually, all of the protocols in Refs.…”