Quantum Key Distribution Using a Single-Photon Added–Subtracted Squeezed Coherent State

We investigate the security of continuous-variable BB84 quantum key distribution protocol using a single-photon added and then subtracted squeezed coherent state (SPASSCS). We find that the SPASSCS is a non-Gaussian and nonclassical state; its non-Gaussianity and nonclassicality are exhibited through the Wigner function. We show that the proposed state is generally robust against the eavesdropping strategies, such as intercept-resend attack and superior channel attack. Further, a comparative study proves the strong efficiency of the proposed state over the coherent state, squeezed coherent state and photon-added then subtracted coherent state. In our analysis, we employ bit error rate, mutual information, and secure key gain.