Quantum Key Distribution using Continuous-variable non-Gaussian States
This work addresses security enhancements in quantum cryptography for secure communication, representing an incremental improvement over existing methods.
The paper tackles the problem of improving quantum key distribution by proposing a protocol using continuous-variable non-Gaussian states (PASCS) with homodyne detection and post-selection, showing increased secret key generation rates and reduced eavesdropper efficiency compared to coherent state protocols.
In this work we present a quantum key distribution protocol using continuous-variable non-Gaussian states, homodyne detection and post-selection. The employed signal states are the Photon Added then Subtracted Coherent States (PASCS) in which one photon is added and subsequently one photon is subtracted. We analyze the performance of our protocol, compared to a coherent state based protocol, for two different attacks that could be carried out by the eavesdropper (Eve). We calculate the secret key rate transmission in a lossy line for a superior channel (beam-splitter) attack, and we show that we may increase the secret key generation rate by using the non-Gaussian PASCS rather than coherent states. We also consider the simultaneous quadrature measurement (intercept-resend) attack and we show that the efficiency of Eve's attack is substantially reduced if PASCS are used as signal states.