Quantum communication satellite is a communication satellite with efficient transmission, a confidential communication technology that completely eliminates spy eavesdropping and cracking, and can counter foreign cyber attacks and defense capabilities.
Purpose: Improve the efficiency of quantum communication.
The reason why it is necessary to launch satellites to establish a quantum communication network between heaven and earth is because the transmission of ground signals mainly uses optical fiber as the medium, and the signal loss during optical fiber transmission is quite serious.
Experiments show that quantum communication signals transmitted through optical fibers are almost completely absorbed after two hundred kilometers. If humans want to achieve long-distance quantum communication transmission, they must establish multiple safe and trustworthy signal relay stations. This Undoubtedly, the probability of information leakage is greatly increased.
Scientists have discovered through research that the energy loss of light is only 20% in the process of penetrating the atmosphere. That is to say, the distance between the sky and the earth is thousands or even tens of thousands of kilometers. The transmission loss is much lower than the transmission loss in the terrestrial optical fiber network
Using this principle, humans can use quantum satellites in space as transfer stations for the terrestrial network, and can establish networks in multiple cities on the ground. Inter-city quantum communication networks will be connected, thereby greatly improving the efficiency of quantum communication.
Extended information
my country’s quantum science experimental satellite weighs about 600 kilograms. The satellite is equipped with payloads such as a quantum entanglement source, a quantum entanglement transmitter, and a quantum key communicator. It can simultaneously establish quantum links with receiving stations thousands of kilometers away on the ground, send entangled photons to distribute secret keys, and use the basic principles of quantum physics to ensure the security of the secret keys.
Ensure unconditional security from identity authentication to encrypted transmission and digital signature, fundamentally solving the problems of confidentiality and information security. Theoretically, quantum communication technology can achieve absolute security in the face of encryption keys distributed by quantum communication.
No one can intercept or copy without being discovered. When faced with encrypted data, due to the complete randomness of the one-time secret key, no matter how large-scale computing resources are called, Neither can be cracked.
Baidu Encyclopedia-Quantum Satellite