Last month, China just launch the first quantum satellite in the world. Now China make the message into quantum level so that is impossible for other countries to crack.
How does quantum satellite work?
In order to make the messages uncrackable, scientists turn to subatomic world. In subatomic level, particles are strange. When they are separated, they continue to affect each other no matter how far they are away from each other. This is what Einstein call spooky action. To pass a message, the satellite will create a quantum key or random numbers that encode information. These would be sent or received to the Earth. Quantum key is able to travel in long distance and carry photons. Photons can not be copied, and photons are always bound with each other. People usually put message in photons. Therefore, no other things in the world can intercept the message. If the message is hacked, quantum key would change or cancel, and the transmission would fail. So that means people can only get some random number if they try hard to crack the message.
Now China launch the first quantum satellite, it not only prove some theories in quantum mechanics, but also is a big step in space race. With the development of technologies, I think more and more countries would be able to launch their own quantum satellite and keep proving the mysterious theories in quantum mechanics.
Chinese Quantum Satellite 墨子（mozi)