Quantum Secure Direct Communication by Using General Entangled States

Abstract

We revisited the quantum secure direct communication (QSDC) by using a notation (Li et al. in Phys. Lett. A 297:121, 2002; Li et al. in Int. J. Theor. Phys. 46 (7): 1815, 2007) and generalized QSDC to arbitrary finite dimensions, we also figured out the decoding formula for QSDC of arbitrary finite dimensions. In order to overcome the channel noisy, we present a scheme through introduce n auxilians by using quantum swapping.

Bidirectional Storing and Exchanging of Quantum Message in a Two-Atom System

“…At last, another bell state measurement is made by Carl on 4 and 5, where Alice and Bob can attain unitary operation from each other through the results of bell states measurement that are published. Following the guide of [22][23][24], we propose an alternative protocol, with the help of a ancillary light, Fig. 2 Simple circuit of the model of bidirectional quantum message temporary storing and exchanging, comprising of four steps, bell stats preparation, two unitary operations, entanglement swapping and bell states reading out Fig.…”

“…Then, Carl measures the two storing qubits and comes out with the result |B 3 12 . Through the decoding equation [24], Alice and Bob can obtain the message from each other.…”

“…When these states are known, the matrix f will be known as well, and the details are shown in [24]. The point here is that no matter what measurement Carl does, he cannot get any message registered in the two storing qubits, for both two matrices U A 1 and U B 2 are unknown to Carl.…”

A New Quantum Proxy Multi-signature Scheme Using Maximally Entangled Seven-Qubit States

“…Wen et al [5,6] proposed some multisignature schemes. Besides, many quantum signature schemes based on quantum mechanics or quantum computing algorithm were proposed [7][8][9][10][11][12].…”

Two Quantum Direct Communication Protocols Based on Quantum Search Algorithm

“…Deng et al [17] proposed a two-step QSDC protocol based on Bell states in 2004. Following the two-step QSDC and the Ping-Pong QSDC protocol, scholars have proposed many QSDC protocols based on single photons [21,22], Bell states [23], multi-particle quantum states [24][25][26] and high-dimension quantum states [27,28]. Long et al [15] reviewed the development of QSDC and DSQC, and presented the criteria for QSDC.…”