Estimating Sources for Weak-Coherent-State-Based Quantum Key Distribution

Abstract

Quantum key distribution allows two parties to generate a shared cryptographic key of bits such that an eavesdropper is not able to obtain significant information about the key without being detected. In protocols based on the transmission of coherent states, the error rate, the key rate generation, and the system security depend on the source states used. In here, we show that quantum homodyne tomography using discretization of the measurements into histogram bin can be used as an estimator to analyze the aforementioned source states without losing too much information.