Quantum Secure Direct Communication: Toward Practical Applications

Gui Lu Long

Prof. Gui Lu Long
Tsinghua National Laboratory for Information Science and Technology
Beijing 100084, P R China

Abstract

Quantum secure direct communication (QSDC) is one major branch of quantum cryptography. Since the first QSDC protocol proposed in 2000, great progress has been made in the past decade. In QSDC, secret message is sent directly over a quantum channel. QSDC offers higher security in transmission because it not only detects Eve, but also nullifies the information when Eve eavesdrops the channel and hence gets no information. In this keynote talk, after briefly introducing the basic ideas of QSDC, I will concentrate on the security proof, experimental implementations of QSDC. It will be shown that QSDC is well within the current technology.

Brief Bio

Dr Gui Lu Long is a professor at Tsinghua University, fellow of IoP (UK) and fellow of APS(US). He is the current president of Associations of Asian Pacific Physical Societies, vice-chair of C13 of IUPAP. He received his B.Sc. from Shandong University in 1982, and Ph.D. from Tsinghua University in 1987 respectively. He has been working in Tsinghua since 1987. During 1989-1993 he was a research fellow in the University of Sussex in UK. His research interests include quantum communication, quantum computing and optical microcavity. In 2000, he proposed the first quantum secure direct communication protocol in the world and other early QSDC protocols later on. He established the phase matching condition in quantum search algorithm, constructed the optimal quantum exact search algorithm, which was called as Grover/Long algorithm by Castagnoli. He experimentally demonstrated several important quantum algorithms in NMR system, such as nonadiabatic holonomic quantum computing, digital simulation of quantum tunnelling and so on. In 2002, he proposed the duality quantum computing formalism which admits linear combinations of unitary operators, which finds important applications in designing quantum algorithms, for instance quantum algorithms for solving the set of linear equations. He and collaborators fabricated an all optical diode using coupled PT symmetric optical micro-cavities.