Towards fast quantum key distribution

Quantum Key Distribution invented in 1984 is an alternative solution to the Key Establishment problem. QKD enables two parties to establish a secret key with secrecy guaranteed by the laws of quantum mechanics. An ideal implementation of QKD requires a practical single photon source which is currently not available. The decoy state protocol uses faint laser pulses with different intensities and allows Alice and Bob to discard key obtained from multi-photon pulses. The remaining of the key is obtained from single photon pulses which are the only ones guaranteed to be secure. The decoy state protocol can increase the distance of transmission and also the rate of secret key generation. In this talk I will present the experimental implementation of a decoy state protocol used for polarization base QKD.