Secure communication with 7 bits per photon

Cryptography is a necessary step in securing communication of sensitive data. The fast development of quantum computing risks to break existing cryptography in the near future. This threatens the security of future communication but also of recent communication that has been stored. Therefore, new methods using quantum technology are being developed for data encryption that can’t be broken by quantum computers.

The new method developed at the University of Twente (UT) is a more sophisticated version of an existing system: Quantum Key Distribution (QKD). Commercial QKD systems are available already from several vendors. They use single particles of light – photons – that can be transmitted over the fiberglass cable grid, in a grid of two polarization directions perpendicular to each other. One direction representing 0, the other 1.