Practical secure quantum communications

Shi‐Hai Sun, Gui‐Lu Long

Deterministic secure quantum communication (DSQC) can transmit ciphered message with information theoretical security, in which the message is directly modulated on the quantum state and transmitted from Alice to Bob. Thus, key is not pre-shared, but rather communicated after the security of the ciphered message transmission is assured. In most of previous DSQC protocols, quantum memory or entanglement is necessary, which is still a big challenge with current technology. And the imperfections of practical devices, such as loss, weak coherent source, and so on, may also down play the security and efficiency of these DSQC protocols. In this article, a DSQC protocol with practical devices is proposed. In our protocol, both quantum memory and entanglement are not require. And DSQC with distance as long as 100–200 km and repetition as high as is possible.

Gui‐Lu Long, Haoran Zhang

Quantum secure direct communication (QSDC) transmits information securely through a quantum channel, distinct among various quantum communications. Proposed by me and Liu 20 years ago, QSDC has now been developed to a stage that is ready for practical application. QSDC advances classical communication of reliable communication over a noisy channel, which is guaranteed by Shannon's theory, to a higher plane of both secure and reliable communication over a noisy channel even in the presence of eavesdropping. Here we briefly introduce the basic principles, the techniques for practical applications.

Christopher J. Chunnilall, Timothy P. Spiller

Ri‐Gui Zhou, Xiaoxue Zhang, Lin-Tao Du