High-dimensional quantum encryption performed in real-world city conditions for first timeThis is useless. There is no shortage of photon, and we can currently send terabits of data thru networks optically.
For the first time, researchers have sent a quantum-secured message containing more than one bit of information per photon through the air above a city. The demonstration showed that it could one day be practical to use high-capacity, free-space quantum communication to create a highly secure link between ground-based networks and satellites, a requirement for creating a global quantum encryption network.
Quantum encryption uses photons to encode information in the form of quantum bits. In its simplest form, known as 2D encryption, each photon encodes one bit: either a one or a zero. Scientists have shown that a single photon can encode even more information -- a concept known as high-dimensional quantum encryption -- but until now this has never been demonstrated with free-space optical communication in real-world conditions. With eight bits necessary to encode just one letter, for example, packing more information into each photon would significantly speed up data transmission.
"Our work is the first to send messages in a secure manner using high-dimensional quantum encryption in realistic city conditions, including turbulence," said research team lead, Ebrahim Karimi, University of Ottawa, Canada. "The secure, free-space communication scheme we demonstrated could potentially link Earth with satellites, securely connect places where it is too expensive to install fiber, or be used for encrypted communication with a moving object, such as an airplane."
As detailed in Optica, The Optical Society's journal for high impact research, the researchers demonstrated 4D quantum encryption over a free-space optical network spanning two buildings 0.3 kilometers apart at the University of Ottawa. This high-dimensional encryption scheme is referred to as 4D because each photon encodes two bits of information, which provides the four possibilities of 01, 10, 00 or 11.
They send 2 bits of data a few hundred feet. To be useful, they would have to send many many orders of magnitude more data, and they also have to hope that someone invents a quantum computer that can be turned into a router. Current routers costs $20 and send 100s of megabits per second. Even with a $50M quantum computer, you would be lucky to get a few kilobits per second.
I am posting this because of the buzzword escalation. It is not enuf to claim "quantum encryption". This claims "high-dimensional quantum encryption". Sounds impressive, right?