ONE GIANT LEAP
In a massive step forward, researchers have sent the first quantum-secured message through the air above a city containing more than one bit of information. This proof-of-concept success means that high-capacity, free-space quantum communication will one day be both a practical and secure process between satellites and Earth—and a worldwide quantum encryption network will also be feasible.
In their demonstration, researchers used 4D quantum encryption to transmit data over a free-space optical network between two buildings. The buildings on the University of Ottawa campus stand 0.3 kilometers apart. The high-dimensional encryption scheme is described as “4D” because it sends more information, as every photon encodes two bits of information.