Defeating eavesdropping with quantum illumination

Abstract

Quantum illumination is a paradigm for using entanglement to gain a performance advantage-in comparison with classical-state systems of the same optical power-over lossy, noisy channels that destroy entanglement. Previous work has shown how it can be used to defeat passive eavesdropping on a two-way Alice-to-Bob-to-Alice communication protocol, in which the eavesdropper, Eve, merely listens to Alice and Bob's transmissions. This thesis extends that work in several ways. First, it derives a lower bound on information advantage that Alice enjoys over Eve in the passive eavesdropping scenario. Next, it explores the performance of alternative practical receivers for Alice, as well as various high-order modulation formats for the passive eavesdropping case. Finally, this thesis extends previous analysis to consider how Alice and Bob can minimize their vulnerability to Eve's doing active eavesdropping, i.e., when she injects her own light into the channel.