Shih-Hung Kao and Tzonelih Hwang, “Multiparty Controlled Quantum Secure Direct Communication Based on Quantum Search Algorithm,” Quantum Information Processing, Vol. 12, Issue 12 (2013), pp 3791-3805.
In this study, a new controlled quantum secure direct communication (CQSDC) protocol using the quantum search algorithm as the encoding function is proposed. The proposed protocol is based on the multi-particle Greenberger–Horne–Zeilinger entangled state and the one-step quantum transmission strategy. Due to the one-step transmission of qubits, the proposed protocol can be easily extended to a multi-controller environment, and is also free from the Trojan horse attacks. The analysis shows that the use of quantum search algorithm in the construction of CQSDC appears very promising.