Experimental Demonstration of Free-Space Decoy-State Quantum Key Distribution over 144km
Abstract
We report on the experimental implementation of a Bennett-Brassard 1984 (BB84) protocol type quantum key distribution over a 144 km free-space link using weak coherent laser pulses. Optimization of the link transmission was achieved with bidirectional active telescope tracking, and the security was ensured by employing decoy-state analysis. This enabled us to distribute a secure key at a rate of 12.8bit/s at an attenuation of about 35 dB. Utilizing a simple transmitter setup and an optical ground station capable of tracking a spacecraft in low earth orbit, this outdoor experiment demonstrates the feasibility of global key distribution via satellites.
- Publication:
-
Physical Review Letters
- Pub Date:
- January 2007
- DOI:
- 10.1103/PhysRevLett.98.010504
- Bibcode:
- 2007PhRvL..98a0504S
- Keywords:
-
- 03.67.Dd;
- 03.67.Hk;
- 42.50.-p;
- Quantum cryptography;
- Quantum communication;
- Quantum optics