Patent ID: 9641326
Date: 2017-05-02
CPC Classifications: H04B,H04L

Claim:
1. A method comprising: emitting from a sender device randomly photons in a first polarization, a second polarization and a third polarization without aligning a polarization system in a plane perpendicular to the first and second polarizations with a recipient device, the recipient device being adapted for detection of photons in association with six polarizations, storing in a memory of the sender device a bit value and a polarization corresponding to each of the emitted photons, receiving information of detected photons from the recipient device in the absence of having sent to the recipient device information about the polarizations used for the emitted photons, determining photons where the same polarization basis consisting of the third polarization and its opposite was used by the sender device and the recipient device and the bit values match between the stored bit value and the received detected photon, error correcting the determined photons using the received information and the stored bit values and polarizations; and constructing a cryptographic key using only the bit values remaining after the error correcting and storing said key in the memory for use with the recipient device.