Measurement-device-independent quantum communication without encryption

October 11, 2018, Science China Press
Illustration of the MDI-QSDC protocol. Credit: ©Science China Press

Quantum secure direct communication transmits secret information directly without encryption. Recently, a research team led by Prof. Gui-Lu Long from Tsinghua University proposed a measurement-and-device-independent quantum secure direct communication protocol using Einstein-Podolsky-Rosen pairs. This protocol eliminates all loopholes related to measurement devices, which solves a key obstacle in practical quantum secure direct communication. The protocol has also an extended communication distance, and a high communication capacity.

Confidential communication is vital in modern society. Quantum secure direct communication is a new kind of secure communication with no encryption. In a classical secure communication, the sender and the receiver have to share a secret key in advance. Then a plaintext message is encoded into ciphertext and sent to the receiver through a classical channel. The ciphertext is then decoded to plaintext by the receiver to complete the communication. In this structure, there exist three potential security loopholes: (1) loss of the key during the distribution process; (2) loss of the key in storage and management; (3) interception of the ciphertext by Eve for later cryptanalysis. With the development of supercomputers and computers, these threats become increasingly serious.

Quantum communication secured by quantum physics principles is an important scheme to resist these attacks. Quantum secure direct communication (QSDC) is a unique type of secure communication that does not require key distribution or key storage and management, and does not use ciphertext. It eliminates the three loopholes in classical secure communication efficiently.

The key problem of practical QSDC is that apparatuses used in practical have some defects, and these imperfections, especially defects in the measurement devices, can lead to leakage of information and affect the security of practical QSDC. Recently, a research team led by Prof. Gui-Lu Long from Tsinghua University proposed a measurement- and device-independent (MDI) QSDC protocol using Einstein-Podolsky-Rosen pairs. This eliminates all loopholes related to measurement devices, overcoming a key obstacle of practical QSDC. Additionally, the MDI-QSDC works over long distances and has high capacity.

Explore further: Physicists use quantum memory to demonstrate quantum secure direct communication

More information: Peng-Hao Niu et al, Measurement-device-independent quantum communication without encryption, Science Bulletin (2018). DOI: 10.1016/j.scib.2018.09.009

Related Stories

'Two-way signaling' possible with a single quantum particle

February 26, 2018

Classically, information travels in one direction only, from sender to receiver. In a new paper, however, physicists Flavio Del Santo at the University of Vienna and Borivoje Dakić at the Austrian Academy of Sciences have ...

Recommended for you

Pushing the extra cold frontiers of superconducting science

October 18, 2018

Measuring the properties of superconducting materials in magnetic fields at close to absolute zero temperatures is difficult, but necessary to understand their quantum properties. How cold? Lower than 0.05 Kelvin (-272°C).

The big problem of small data: A new approach

October 18, 2018

Big Data is all the rage today, but Small Data matters too! Drawing reliable conclusions from small datasets, like those from clinical trials for rare diseases or in studies of endangered species, remains one of the trickiest ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.