A satellite launched earlier today is designed to distribute quantum-encrypted keys between relay stations in China and Europe. If it goes as planned the result could enable unprecedented levels of security between parties on different continents.
It uses quantum cryptography and is similar to existing fibre-based quantum key distribution networks in Europe, China, and the US. The way we understand it, it works by the monitoring the noise of quantum cats either dying or mewing with life. This allows distant parties to obtain identical random strings of data without being intercepted by outside parties. The plus side is that the systems resist nearly all conventional forms of decryption.
China’s new satellite would put that same system to work over the air, using high-speed coherent lasers to connect with base stations on two different continents. The experimental satellite’s payload also includes controllers and emitters related to quantum entanglement. It is still experimental as it has not been tried from space before and there is no guarantee it will work and the cats will co-operate.
The Chinese have done well on this. The project was pitched to the European Space Agency in 2001, but it could not get funding. The professor who first proposed the system, University of Vienna physicist Anton Zeilinger, is now working on the Chinese project.