Figure 1. (Color online) The four initial MDI-QKD experiments.

a, Proof-of-principle MDI-QKD with time-bin encoding (Rubenok et al., 2013). b, Full MDI-QKD implementation with random modulations of states and decoy intensities based on time-bin encoding (Liu et al., 2013). c, Proof-of-principle MDI-QKD with polarization encoding (Ferreira da Silva et al., 2013). d, Full MDI-QKD with random modulations of states and decoy intensities based on polarization encoding (Tang et al., 2014b). [Figures reproduced from (Liu et al., 2013; Rubenok et al., 2013; Ferreira da Silva et al., 2013; Tang et al., 2014b)]

Professor Pan Jianwei, Professor Xu Feihu and Professor Zhang Qiang from the University of Science and Technology of China (USTC), collaborating with Professor Ma Xiongfeng from Tsinghua University and Professor Hoi-Kwong Lo from the University of Toronto, were invited to publish a review entitled “Secure Quantum Key Distribution with Realistic Devices” in the Reviews of Modern Physics on May 26.

Quantum communication is an important branch of quantum information science. It refers to the communication technology that uses quantum bits as information carriers for information transference.

One of the most typical applications of quantum communication is quantum key distribution (QKD). QKD is the only means of communication so far with strictly proved security. It is also the first quantum information technology to move from the laboratory to practical application, and as such is one of the most dynamic frontiers in physics.

In recent years, with the development of practical QKD research, the realistic security of QKD has been of great interest globally. The potential security risks and solutions introduced by devices in actual systems that do not fully conform to the mathematical model of the protocol have been extensively studied. It’s worth mentioning that Professor Pan's team experimentally realized several important new protocols for the first time anywhere in the world.

This paper reviews the development history of quantum cryptography in detail, discusses the practical security of quantum key distribution in depth, and forecasts the future development trend of QKD technology. Through more than 30 years of joint efforts by global researchers the security of practical quantum cryptography has been established. In particular, proposed QKD protocols, such as the measurement-device independent (MDI) protocol, remove the security risks that may occur in the physical realization of quantum cryptography and pave the way for quantum cryptography based on real devices.

A special comment published in the journal states that this review gives both sides of the story, combining the current best theory of quantum security and an extensive survey of what makes a quantum cryptosystem safe in practice.

Reviews of Modern Physics is a most authoritative review journal in the field of physics with an average impact factor of over 40 in the past five years. It publishes only about 40 academic papers every year. This is the second review paper published by Professor Pan’s team, and is also China’s second review paper published in this journal in quantum information science; confirmation that China continues to maintain its international leading position in quantum communication.

Written by Lu Hongyu, edited by Jiang Pengcen, USTC News Center

For more information, please contact:

Prof. Pan Jianwei

E-mail: panjw@ustc.edu.cn

Source: University of Science and Technology of China,

Chinese Academy of Sciences