Modulation leakage-free continuous-variable quantum key distribution

Abstract Distributing cryptographic keys over public channels in a way that can provide information-theoretic security is the holy grail for secure communication. This be achieved by exploiting quantum mechanical principles so-called key distribution (QKD). Continuous-variable (CV) QKD based on coherent states, particular, an attractive scheme communication since it requires only standard telecommunication technology operate at room temperature. However, recently discovered side-channel created process of state preparation leads to leakage information about transmitted state, opening loophole eavesdroppers compromise CVQKD system. Here, we present system without this modulation vulnerability. Our implementation baseband approach and uses in-phase quadrature (IQ) modulator radio frequency heterodyne detection together with carefully designed digital signal processing measurement. We consider practical aspects demonstrate generation composable secret against collective attacks. work step towards protecting systems imperfections physical devices operational limitations performance degradation.