Controlled Quantum Secure Direct Communication Based on Four-Qubit Cluster States and Quantum Search Algorithm

Abstract

A controlled quantum secure direct communication protocol based on four-qubit cluster states and quantum search algorithm is put forward, in which four users, a sender, a receiver and two controllers, are involved in achieving the secure transmission of secret message. The four-qubit cluster state can ensure the feasibility and security of the protocol because of its large persistency of entanglement. Meanwhile, the idea of quantum search algorithm is used to accomplish the task of encoding and decoding secret message. The proposed protocol can successfully avoid the information leakage problem and resist some common attacks including the outsider attacks and the internal attacks, and its qubit efficiency is up to 20%. Furthermore, compared with the previous quantum secure direct communication protocols, it can effectively resist the attacks from the dishonest receiver.

Scheme for implementing nonlocal high-fidelity quantum controlled-not gates on quantum-dot-confined electron spins using optical microcavities and photonic hyperentanglement

“…One of the ultimate directions for the development and integration of quantum information technology in the future is to construct quantum information networks [7][8][9], which are considered as spatially separated quantum network nodes connected by quantum communication channels. The fundamental characteristic of quantum networks lies in the capability to nonlocally transmit not only quantum states but also quantum operations between different quantum nodes, which makes it essential for various applications such as quantum secure direct communication [10][11][12][13][14][15] and secure multi-party quantum computation [16][17][18][19][20][21]. The quantum network can therefore significantly improve the power of quantum information processing (QIP) compared with individual QIP systems.…”