A few days ago, Pan Jianwei, a professor at the University of Science and Technology of China and an academician of the Chinese Academy of Sciences, and his collaborators published a paper on Nature, officially announcing the verification of the technical feasibility of a large-scale quantum communication network integrated with the world.
On January 12, Huawei Technologies Co., Ltd. was authorized to publish a patent related to “a quantum key distribution system, method, and equipment”, with the authorization announcement number CN108737083B.
According to the patent abstract, the quantum key distribution system helps reduce the complexity and cost of quantum key distribution, including the first communication device and the second communication device , Third-party systems, first measuring equipment and second measuring equipment.
The first measuring device is used to determine the receiving position and receiving time of the first photon sent by the first communication device, and the receiving of the third photon sent by the third-party system The first receiving response is generated after the position and receiving time meet the preset pattern; the second measuring device is used to determine the receiving position and receiving time of the second photon sent by the second communication device, and the receiving of the fourth photon sent by the third-party system The second receiving response is generated after the position and the receiving time meet the preset pattern.
The first communication device and the second communication device respectively determine the bit value according to the phase of the photon after receiving the first reception response and the second reception response, and determine the The bit value is saved as a shared quantum key.
According to the website of the State Intellectual Property Office, the patent application date for this invention is April 24, 2017, and the application publication date is November 2, 2018.
Huawei’s deployment in the field of quantum secure communications is not new. As early as 2018, Huawei and Telefónica cooperated to complete an experiment on the distribution of excessive subkeys on commercial optical fiber networks. The field experiment used the optical infrastructure provided by Telefónica to connect three sites in the Madrid metropolitan area. Among them, the software controlled CV-QKD equipment developed by the Munich Huawei Research Laboratory and UPM was installed.
So, how does quantum key distribution specifically integrate with classical communication infrastructure?
If a randomly generated code is encoded in the quantum state of a photon, according to the quantum unclonable theorem, an unknown quantum state cannot be accurately copied, once it is measured Will be destroyed. Therefore, once someone steals and tries to read the volumeThe subkey will definitely be discovered. This kind of password generation method that does not rely on computational complexity but is based on the basic principles of quantum mechanics is quantum secure communication.
In practical applications, quantum key distribution needs to be used in conjunction with cryptographic algorithms, through “quantum channel + classical channel”: quantum channel transmits quantum signal, classical channel Interactive processing method of extracting the security key from it.
Therefore, the deployment of the quantum secure communication network is also completed on the existing optical fiber network infrastructure: the equipment is deployed in the computer room and site of the optical network, and the quantum encryption Key distribution (QKD) technology distributes keys in communication links and networks to form a quantum secure communication network.
On the user side, the quantum network supports the access of downstream applications in the government, finance, and power industries for secondary development.
It can be said that no matter from the device or application level, communication providers have the advantage of being the first to explore quantum key distribution.
In 2019, the ITU (International Telecommunication Union) decided to establish a “Network-oriented Focus Group on Quantum Information Technology” (FG—QIT4N), becoming the first in the International Organization for Standardization The 9 member units behind the Quantum Information Technology Focus Group include Huawei.
It can be imagined that in the future, communication equipment suppliers like Huawei will play a more active role in the construction of quantum secure communication networks.