Decoy state quantum key distribution in telecom dark fiber
Wei Chen, Zheng‐Fu Han, Zhen−Qiang Yin, Qing-Lin Wu, Guo Wei, Guang‐Can Guo · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2007
The imperfect components of a quantum key distribution (QKD) system will degrade its security. The highly attenuated weak coherent laser source used in today's QKD system is vulnerable to PNS attacks due to multi-photon optical pulses. Decoy State QKD, which is capable of beating PNS attacks and providing unconditional security, has been an attractive scheme recently. We have used a one way Faraday-Michelson phase modulated QKD system to implement 123km decoy state QKD in the lab. Furthermore a field decoy state QKD experiment of 32km dark fiber in Beijing is fulfilled. The optical pulse repetition rate is 1MHz and the final secure key is 9.59×10-7 (6.784×10-6) bit per pulse for 123km (32km). The experiment result indicates that the decoy state scheme can be successfully used in real-life metropolitan QKD sessions.