Implementation of polarization-coded free-space BB84 quantum key distribution

Y. -S. Kim, Y. -C. Jeong, Y. -H. Kim
2008 Laser physics  
We report on the implementation of a Bennett-Brassard 1984 quantum key distribution protocol over a free-space optical path on an optical table. Attenuated laser pulses and Pockels cells driven by a pseudorandom number generator are employed to prepare polarization-encoded photons. The sifted key generation rate of 23.6 kbits per second and the quantum bit error rate (QBER) of 3% have been demonstrated at the average photon number per pulse µ = 0.16. This QBER is sufficiently low to extract
more » ... low to extract final secret keys from shared sifted keys via error correction and privacy amplification. We also tested the long-distance capability of our system by adding optical losses to the quantum channel and found that the QBER remains the same regardless of the loss.
doi:10.1134/s1054660x08060212 fatcat:fxs74kmd3rbdhg7vmrcvua4q5m