Two scientists in Austria and China have held the first intercontinental video conference to have been encrypted using quantum technology.
In the Alice in Wonderland world of the incredibly small, things can be in two places at once, merely looking at a particle can alter its twin on the other side of the universe at the same time, and theoretical cats can be both alive and dead.
This sounds almost unbelievably odd but the physics that explains it has some important real-world implications.
And one of those is encrypting communication so there is no chance of anyone – be they hackers, spies or the security services – eavesdropping on private conversations.
A statement issued by the Chinese Academy of Sciences reported that its president, Chunli Bai, had held a video conversation with his counterpart at the Austria Academy of Sciences in Vienna, Anton Zeilinger, in the “first real-world demonstration of intercontinental quantum communication”.
“Private and secure communications are fundamental human needs,” the statement said.
“In particular, with the exponential growth of Internet use and e-commerce, it is of paramount importance to establish a secure network with global protection of data.
“Traditional public key cryptography usually relies on the perceived computational intractability of certain mathematical functions.
“In contrast, quantum key distribution (QKD) uses individual light quanta (single photon) in quantum superposition states to guarantee unconditional security between distant parties.”
Technical reasons had previously limited such conversations to distances of a few hundred kilometres, the academy said, but they had found a “promising solution to this problem” involving a “sophisticated satellite, named Micius”.
It is equipped with “a decoy-state QKD transmitter, an entangled-photon source, and a quantum teleportation receiver and analyser”. Five ground stations have also been built in China and Tibet.
The Chinese science academy said the encrypted communication system was being trialled for potential “real-world applications by government, banks, securities and insurance companies”.
There are plans to carry out similar test conversations between someone in China and four other places, Singapore, Italy, Germany and Russia.
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