Enhancing practical security of quantum key distribution with a few decoy states

摘要

Quantum key distribution establishes a secret string of bits between twodistant parties. Of concern in weak laser pulse schemes is the especiallystrong photon number splitting attack by an eavesdropper, but the decoy statemethod can detect this attack with current technology, yielding a high rate ofsecret bits. In this Letter, we develop rigorous security statements in thecase of finite statistics with only a few decoy states, and we present theresults of simulations of an experimental setup of a decoy state protocol thatcan be simply realized with current technology.